Printable Version of Topic

Posted by: '73-914kid Nov 8 2008, 08:47 AM

Okay guys.....I'm letting the motor bit set, so I'm on to suspesnion (something I can actually work on right now) and I need a new set of trailing arm bushings.
I was looking into the Weltmeister Polygraphite bushings because they were a decent price.

Anyone have other opinions on these bushings or other ones for below $80? I would love poly-bronze bushings but $260 from pelicanis just a little steep

Posted by: Dave_Darling Nov 8 2008, 10:06 AM

They stick, they squeak, and they're a bit of a pain to install correctly. (Just ask JP!) The price is kinda nice, though!

The sticking can be fixed if you install them carefully enough, I think. You can cut a channel and add a Zerk fitting so you can re-grease them periodically so they don't squeak.

--DD

Posted by: r_towle Nov 8 2008, 11:04 AM

What is the long term purpose of the car?
Given the difficulty of installing any rear trailing arm bushings, dont take the choice lightly.

The plastic bushings wont last and will squeek. they oval out in a year or less, so you are doing it again...
In the long run factoring in time and aggravation, replacement, reworking etc...you will end up throwing out the plastic bushings fairly soon after you install them...

If its a street car, keep the rubber, its better and more supple.
If its autox or race go with the Bronze from Elephant racing or the linear bearings from Shine Racing.

Rich

Posted by: J P Stein Nov 8 2008, 11:13 AM

Yes, Dave, they ain't worth shit, however......
If your bucks down and your rubber bushings have disintegrated......they will dufernow, like Rich said, maybe a year of squeaking....I had no such excuse.

Go with Elephant iff'n you can swing it.
Shine/Tarett needles if you want the best....not cheep.....but I'm not too sure of those for longevity on the street.

Posted by: jimkelly Nov 8 2008, 01:32 PM

is bronze $260 per side with axle - or $260 for both sides with 2 axles?

jim

Posted by: Lou W Nov 8 2008, 01:59 PM

Both sides of the rear.....I installed them and I think they are the way to go.


Attached image(s)

Posted by: Eric_Shea Nov 8 2008, 02:09 PM

Here's my take on the level of quality on the rear bushings:

1. FreeMotion (bearings) -or- Elephant Bronze (it's hard to pick).
2. The harder 70D poly bushing.
3. I don't even recommend the softer poly bushings you're looking at for all the reasons that Rich mentions.

The more expensive ones (Elephant/FreeMotion) will hopefully last a life time and as mentioned, this isn't a job you want to do every couple of years. I'm using FreeMotion on my 914 and Elephants on my 911.

I used the soft poly bushings on my 911 years back and they distorted and squeaked. As mentioned, I replaced them soon after I got them (well... a couple years but, that's too soon to be doing this job again). I've even seen them take out front suspension pickup points on a 911.

The harder Poly bushings do not exhibit the same wear characteristics of the softer poly (meaning, they'll last a long time... if properly taken care of, probably as long as the stock ones did), they won't squeak and give virtually the same characteristics as the solid bushings.

With the harder poly bushings you will need to prep them properly to get them to operate noise free. They need to be honed to a perfect fit on your arm otherwise they can bind and clack or, if they're too loose they can do the same. Here's what I like to use now:

http://www.mcmaster.com

Item #4719A261 Sleeve
Item #4650A68 Drum

With this is a lower speed drill press you can virtually guarantee a perfect fit on your control arm shaft. It only takes a few minutes with this set up and it's very precise.

Once the bushings slide freely on the shaft (while cool) you can install them and put zerk fittings on the arm to keep them lubed.

At $20.00 a set, I find them an excellent bushing if your budget is such.

Posted by: Eric_Shea Nov 8 2008, 02:14 PM

BTW

Posted by: '73-914kid Nov 9 2008, 05:24 PM

The car is going to be a daily driver for the street. The rubber bushings have pretty much disintigrated and cracked pretty bad.

Where could I find new rubber bushings? All I can find are polyeurathane........

Posted by: Joe Ricard Nov 9 2008, 05:53 PM

not going to find new rubber. unless you buy a whole new trailing arm.

Get the poly and install a grease fitting it will last at least a year.

I did something similair to the McMaster carr pieces. I used steel bushings with grease clearance of .002 and of coourse a zerk.

No stick, no bind, no play. Lots of noise from the road.

Posted by: Eric_Shea Nov 9 2008, 06:08 PM

Elephant Racing does rubber now. If you don't like the price of their poly-bronze you won't like the rubber.

http://www.elephantracing.com/suspension/rubberbushings/914rubberbushings.htm

They are the only ones I know of doing it for the 914 right now.



The harder poly will probably last a lifetime. They are extremely hard at 70D (rated at 9000lbs). There is no flex, no stick or bind when honed properly so it would be more like Joes metal bushings. I've done dozens now and they slide up and down in the mounts with one finger ease.

http://www.pmbperformance.com/catalog/item/1925565/5297602.htm

Standard 94A polys flex a lot, you can squeeze them with your hand. Those are the ones that will last a year or two.

Posted by: Eric_Shea Nov 9 2008, 06:10 PM

Lou,

I think your outside zerks are on 180 degrees off on the tube. They'll probably interfere with the outer control arm mounts.

Posted by: wbergtho Nov 9 2008, 06:16 PM

This is what I did and haven't had a problem in over 5 years.

Posted by: Gint Nov 9 2008, 07:14 PM

That price isn't bad actually. IMO anyway...

Posted by: Eric_Shea Nov 9 2008, 07:18 PM

Agree... if you want the ultimate restoration deal it's a great way to get new rubber. In speaking with Chuck I believe they have the arms powdercoated as well.

I was just going off this comment.

Posted by: r_towle Nov 9 2008, 07:21 PM

That price is pretty decent.
Did I miss a DIY price for the rear trailing arms???

RIch

Posted by: ConeDodger Nov 9 2008, 07:21 PM

I agree... I just did this and it looks like your outer one will be buried inside the mount when installed while your inner will be pointing up into the body when the suspension is free hanging and impossible to service. I suppose you could drop them to service them each time... I wouldn't but it could be done.

Posted by: Lou W Nov 9 2008, 07:22 PM

Yup, Eric and Rob you're both right, I fixed them before I installed them.

Posted by: ConeDodger Nov 9 2008, 07:28 PM

I would have done the same thing but our Car Of The Month boy Paul Sayegh warned me to mock install them and mark them... Otherwise I would have picked the same spot, in fact I had Sharpie marker in the same spots

Posted by: Lou W Nov 9 2008, 07:37 PM

I didn't think the instructions were very clear, then I had a tough time trying to find someone who had a replacement zirc fitting, mine broke off when I mounted one of them. Elephant Racing guys were very helpful in rushing me out a replacement.

Posted by: Eric_Shea Nov 9 2008, 09:05 PM

I don't think they're a DIY item. It sounded to me like these had to be done there. We were talking and Chuck started crunching numbers etc. frankly, I don't think he has a huge margin in them at that price. It sounded rather labor intensive.



They show the placement they just don't mandate it which I think they should. I have a big bag of bleeders here of the M6 variety. I don't like the M5x.8 they supply them with because (all together now) they can break off when mounting them. I've probably installed dozens of them and after the second one I knew it was time for a solution.

Posted by: r_towle Nov 10 2008, 10:08 AM

Shipping trailing arms from the East Coast kills this...add another 100 plus to get them there and back again.

It really cant be that hard...yes its labor intensive but if he can make the same margin without touching the trailing arm...why not...

It would just need some simple instructions.

Rich

Posted by: Eric_Shea Nov 10 2008, 10:20 AM

Yup, and that's the cheap guys.

I think it's tools more than anything. It sounded a bit different than the 911 units as these are housed in the tube. They have those videos that show the installation of the fronts and they look fairly simple.

I'll try to give him a call today and get more details.

It's still good to know there's a resource if someone was doing a full concours resto.

Posted by: r_towle Nov 10 2008, 10:47 AM

well I shipped two heads to CA for 50 bucks...just under that.
One trailing arm from here is probably 100 bucks each way....see the problem...

so add 300-400 for shipping...that kills it.

Ask if the process requires anything that cannot be purchased...tools etc.
I would be willing to do an East Coast setup for them...meaning I could do any arms that need it done in my neck of the woods...a territory deal...

Or, just figure out a way to sell them DIY form.
Rich

Posted by: Eric_Shea Nov 10 2008, 10:57 AM

That's exactly what our last conversation was. He mentioned it to me then he started crunching the numbers on the calculator and I got the feeling he was running out of margin...

I use USPS when shipping our 5-Arms out and it would probably be around $45 one way for you (no insurance etc.). They have to really be packed well etc. to as they tend to arrive with a cardboard "thing" wrapped around them held together by tape.

Two arms loaded is 50lbs. You could probably shave an additional 7-10 off by yanking hubs and bearings first.

Let me check with him and see where he is with it. I'll let him know there's interest.

Posted by: jimkelly Nov 13 2008, 06:54 PM

ERMP-2051500 Elephant Racing, Front PolyBronze Suspension Bushings, Set of 4, 914 1.7/1.8/2.0 (1970-76), 914-6 (1970-72) [Photo]
$260.00

ERMP-2400800 Elephant Racing, Rear PolyBronze Suspension Bushing Set, 914 1.7/1.8/2.0 (1970-76), 914-6 (1970-72) [Photo]
$315.00


ok - the fronts are a set of 4

are the rears a set of two axles and four bearings??

jim

Posted by: TC 914-8 Nov 13 2008, 07:17 PM

This link and #'s takes me to sanding drums, am I missing something?

I see they have a good selection of bushings and sleeves. Is that where the link is supposed to end up? And is that what you use?

Posted by: Eric_Shea Nov 13 2008, 07:44 PM

Tony,

Those are the items I use to hone out the solid bushings. They need to be honed properly otherwise; too loose - they can rattle. Too tight - they can squeak.

This is probably the link you're looking for:

http://www.pmbperformance.com/catalog/item/1925565/5297602.htm

Jim, you are correct on the Elephant parts. The Elephant rears come with shafts and bushings that are already matched and machined to fit. The hard poly and Delrin bushings need to be honed to your specific arms.

Posted by: TC 914-8 Nov 13 2008, 08:02 PM

Yep, I was just surfing their site and got side tracked on the brake caliper rebuilding kits. Caliper widening kit and vented rotors. It never ends!!!!

So, I do have a squeeking on the drivers side rear as I get in and out of the car. I jacked up the side for inspection and can see, and feel rubber bushings. the P.O. had installed the trailing arm stiffining kit along with a chasis stiffining kit. I would think while having that work done, He would go in with new bushings, if so they must be the rubber type.
I did spray some teflon lube in the joints and on the shock bushings, the squeek is gone for now. I guess the best way to check the condition is to pull the control arm and give it a eyeball.
If I do dissasemble the mounts and remove the trailing arm. will I have to have the rear end aligned?

Tony

Posted by: Eric_Shea Nov 13 2008, 08:08 PM

Yup.

It sounds like he put the 94D poly bushings in there. They were about all you could get for a while there. Very common, hence a lot of people hate them.

You should be able to get under the car and have a look and a poke. Push a screwdriver into the rubber area and see how soft it is. The inner mount is probably the easiest for this as the outer mount/body flange can get in the way.

The softer poly bushings look just like the harder ones but they can wear prematurly and squeak like you're describing.

Posted by: dashgod Feb 3 2009, 06:03 PM

I'm just about to tackle this project myself. I was wondering if anyone has any pictures, video, or other advise on techniques for spiralling or grooving the bushings for the grease.

Posted by: Krieger914 Feb 3 2009, 07:40 PM

I don't have any photos, but have had weltmeister bushings in my car front and rear for about 9 years and 11k mile with no slop or sqeaking. I autocross this car all the time. I have been very happy and have no plans for removal. I temporarily put the bushings on the controll arms and found a good place to put a zerk fitting that would not interfere with movement, then drill a hole, roughly where the center of the bushing is, through both the metal arm or bearing retainer into the plastic bushing. Then remove the bushing drill the hole all the way through. Give the bushings to a machinist and have him put the slightest groove on the id and od of each bushing. I used small washers under some of the zerks so they would not interfere with the movement of the bushing. I squit two shots of swepco moly lube into each zerk every year. I think I used 4mm zerks. I don't know if what I bought 10 years ago is the same as now.

Posted by: Eric_Shea Feb 4 2009, 03:53 PM

Here's a write up on it. I like the sanding drum listed in this thread better than the small cylinder hone listed in the link.

http://www.914world.com/bbs2/index.php?showtopic=79299

I've done spiral grooves in the past and I don't think they're needed. I would just lube up the bushing until grease starts to come out the end and you should be good to go. Check and relube every six months or so.

Posted by: SirAndy Feb 4 2009, 04:15 PM

I've been running the roller bearings (now http://www.originalcustoms.com/FreeMotion.php) for over two years now and i'm very happy with them.

Andy

Posted by: degreeoff Feb 4 2009, 04:17 PM

does anyone know off the top of their heads what size the inside and outside of the rear shafts are as well as the size of the front A arm? I don't see whay we (buy in bulk) couldnt just go through McMastercarr to get the parts for a roller for a HELL of a lot less than the others charge?

http://www.mcmaster.com/#ball-and-roller-bearings/=gl1jy

http://www.mcmaster.com/#thrust-bearings/=gl45s


Josh (the poor one)

Posted by: andys Feb 4 2009, 05:01 PM

Josh,

You'll also need a new pivot shaft made with heat treated and ground surfaces for the needles to ride against. Can't use the stock pivot shaft unless someone has figured out a way to add some kind of hardened sleeve over it. I've never done one, but that's how I figure it.

I machined a set of bushings from Delrin; I believe someone here makes those as well.

Andys

Posted by: jmill Feb 4 2009, 05:18 PM

A little time with a caliper should be all you need. I've got a set on my garage floor right now. Looks like I found my weekend project.

Posted by: degreeoff Feb 4 2009, 05:44 PM

Take measurements for me as I do not want to undo my suspension to make mine yet....PLEASE?

Posted by: SirAndy Feb 4 2009, 05:54 PM

You guys do realize that you can't use the stock shaft with roller bearings, do you?
Andy

Posted by: jmill Feb 4 2009, 05:55 PM

I can take measurements. I don't believe it's perfectly round and will need some cleanup. Andys is correct though. The needles will need to ride on a smooth hardened surface. It looks like around $50 in bearings for the rear. The shaft is another story.

Posted by: SirAndy Feb 4 2009, 05:59 PM

And the new shaft has to be a tight press fit into the trailing arm. The only movement should be the bearings against the shaft surface.

Unless, of course, if you want the "random alignment change under load" option ...
Andy

Posted by: jmill Feb 4 2009, 06:04 PM

Yeah. That's the kicker but my fathers a TV repairman with a killer set of tools. I like the sleeve approach myself. Doesn't hurt to look into the options.

Posted by: Eric_Shea Feb 4 2009, 06:09 PM

Both shafts and arms are in consistent. I've seen and measured "hundreds" of both.

Easy to run out and grab bearings from McMaster et al. Then you need to have race$ made for both the ($milled$) shaft and the arms. Cheap is no longer cheap.

I'd say McMarkster is better than McMaster for this dealie-o.

Posted by: Racer Chris Feb 4 2009, 06:40 PM

That would be me, ie. CFR-Tangerine Racing Products.
We also have brand new pivot shafts made of heat treated steel (4342PH I think). The shafts have the same dia as original, but are precisely machined. They also have identical ends to the originals instead of threaded holes.

Delrin is a machine-able engineered thermoplastic with high lubricity, as opposed to the polygraphite bushings which are cast plastic (crap, imo) that is not machine-able and they usually do not fit tightly enough in the housing. We ream our delrin bushings after installation to ensure true roundness and concentricity end to end, as well as a close tolerance fit on the shafts, without any binding. Both the needle bearing and polybronze systems rely on a looser fit because they have no way of ensuring concentricity.
IMO, our delrin assemblies are every bit as good as the needle bearing and polybronze systems. All three are head and shoulders above the polygraphite product, which was the standard for many years.

Posted by: degreeoff Feb 4 2009, 09:12 PM

BTW..... .....sorry



It looks like that is how its done here.....a couple sleaves an inner and outer. Are they then pressed on the shafts? for the front and the back? The other option is of course doing the polybronze setup which McMaster has as well.

Posted by: SirAndy Feb 4 2009, 09:21 PM

That's a schematic of McMark's front roller bearings. You need two of those per A-Arm.

The rears are completely different ...
Andy

Posted by: degreeoff Feb 4 2009, 09:42 PM

Did McMark design and market that design?

Posted by: SirAndy Feb 4 2009, 10:06 PM

Mike Mueller did the original design and sold them as "Mueller's roller bearings" for a while.
When Mike sold his 914 and got out of the parts business, Mark bought the design and left over stock and is now selling them as "FreeMotion" roller bearings ...

I've got a set of rears on my car. The fronts i have yet to install. I know of at least 6 or 7 cars here in the bay area that run them (front and/or rear).
Andy

Posted by: Eric_Shea Feb 4 2009, 10:48 PM

I believe Harvey Shine (sic) first developed the whole roller bearing thing. Mike Mueller asked Harvey for permission to design something similar. Harvey said "sure". (all 3rd party bla, bla, bla... take it for what it's worth).

I too have Marks kit on the back and the fronts will be done soon, hopefully this month. I like what Mark has done with the kit and the rears.

Regarding Poly: I think the softer 94D stuff is crap but I'm very impressed with the 70D stuff if it's installed properly. We've done installs with no slop, no noise and smooth one finger operation. All on a bushing that's rated at 9000lbs.

Posted by: Racer Chris Feb 5 2009, 08:11 AM

Dick Shine of Shine Racing in Walpole Mass is the designer.
Brad R. stole (a habit of his) the idea from him after pressuring Dick to lower his prices and he refused.
Brad then convinced Mike to make them in his garage.

For what its worth, I had already installed a set of delrin bushings on my race car before I knew something else, better than weltmeister poly, was available. I was shown a set of needle bearing assemblies by Dick at his shop in 1998.

Posted by: Racer Chris Feb 5 2009, 09:08 AM

More than 50% of the trailing arm pivot shafts we remove look like this:


After sanding on the belt grinder it is down to the original diameter again:


but, after wire brushing, the deep pits that remain are evident. Installing this shaft into any plastic bushing can't be good for longevity:


I was having the best shafts that I could find centerless ground for a while to true them up without removing too much material. What I found was that the shafts aren't straight enough to true them with removal of only 2 thou diameter, and if there are any pits the .002 removed doesn't get rid of them.
So I designed new shafts that are more precise and stronger than the originals:

Posted by: Racer Chris Feb 5 2009, 09:18 AM

Our delrin bushings have a light press fit into the trailing arms. This means the id is no longer the correct dia or round any more so we ream them precisely using our "home-made" tools. The trailing arm bores also aren't quite straight relative to each other. Reaming or honing each one independently means they aren't going to be concentric. The id has to fit more loosely in order that the shaft doesn't bind when inserted through both ends.

This method is hardly precise, lol:


The long shaft added to our reamer allows it to align from the bushing at the other end, thereby ensuring concentricity of the two bores.
The modified pivot shaft holding the lathe tool bit is used to cut the end of the delrin bushings precisely. This ensures that the pivot shaft will be about .005" longer than the bushing end to end dimension so no side play or binding is evident after installation in the chassis.

Posted by: degreeoff Feb 5 2009, 09:44 AM

dat dare is preety schwanky my man!

Posted by: jmill Feb 5 2009, 10:43 AM

Yeah I'm with you here. I'll put away my caliper and start saving. After looking at Chris' setup it's not worth re-inventing the wheel, so to speak. I'm not into mass production. That's about the only way you could recoup tooling costs.

Posted by: andys Feb 5 2009, 02:32 PM

Perhaps someone has cut open a pivot shaft, but a couple of years ago I x-rayed one out of curiosity (didn't want to destroy it). It is a simple tube with machined segments welded on each end. Nothing particularly tehnical about them.

I agree that Chris' method assures proper axial alignment of the two bushings; otherwise it's only a best guess.

Andys

Posted by: finstermojo Feb 5 2009, 04:47 PM

I purchased some bushings a while back about a year ago off ebay for the front and rear all i remember is them being black is there any way to tell weather they are delron 94a or 70d how can i tell?

Thanks

Posted by: Eric_Shea Feb 5 2009, 07:47 PM

How much did you pay?

Here's the real determining factor; squeeze them. If you can distort them with your hand, they are "not" Delrin or 70D. If they do not bend or flex consider yourself lucky. They will have to be either machined or honed to fit but that's a good thing.

Posted by: charliew Feb 5 2009, 09:17 PM

I know this started as a rear bushing thread but this is what I have researched on the fronts.

Are weltmeister considered hard or soft? I have a front set already installed with zerts in the housings and they seem pretty hard. I don't think they are as hard as delrin but they seem hard enough.

For the front the housings seem to be 2.0 id x 2.0 wide and the a-arm shaft od seems to be slightly less than 1.5 which might be a problem without making a sleeve to repair or size the part the bushings go on, to 1.5.
These bronze bushings for the front I found at McMaster Carr seem to be the right size: 7965k58 1.5ID x 2.0 OD 2.0 inches long 25.13, If you want 2.5 long and cut them to exact length go with, 7965k57 27.60, or get a 4.0 long one and cut it in half 37.29,
Theres a bronze thrust thats 2.5 od flange, 1.5 id,x .125 thick. 7814k39 5.30.
If I were to go this route I think I could sand the od down and put them in with jb weld into the housings and add the zerks.

It's at least 95.00 for the bronze parts and thats not counting a a-arm shaft sleeve x 4 if it's needed.

I read the install on one of the sites and they use jb weld to install the inner sleeves on their shafts.

I think the rear might be done the same way with putting sleeves on the shaft ends and making them smaller than the sleeves and using jb weld to center them in the bushings, or using jb weld to locate the bushings in the rear control arms.

Posted by: r_towle Feb 5 2009, 09:37 PM

I am also running the linear bearings from the original designer/manufacturer, Shine racing www.srsvw.com
I am still quite happy with them.

Rich

Posted by: finstermojo Feb 9 2009, 04:49 PM

So this is a picture of the bushing i purchased over a year ago, what do you think are they the soft or hard bushings. This was the most i could bend it before eating my spinach either way it might pay to get the ones PMB are selling for $20.

Thanks
Matt

Posted by: Eric_Shea Feb 9 2009, 04:53 PM

Pretty obvious.

That's a perfect example of a softie.

Posted by: finstermojo Feb 9 2009, 05:51 PM

I just ordered a set of hard bushings from your place do you have the front set?

Posted by: r_towle Feb 9 2009, 06:03 PM

3-4 years now...still swing like butter.

Rich

Posted by: J P Stein Feb 9 2009, 06:09 PM

Swing is a foregone conclusion, but is there any slop....lateral or axial.
My needles are still tight but wear was evident on the thrust washers.
I turned them over.

BTW, Rich, I had the tranny down & found a broken needle bearing cage under first gear. The needle was still in place but the cage was cracked thru side to side. That coulda got ugly.


Attached thumbnail(s)

Posted by: Eric_Shea Feb 9 2009, 07:06 PM

No fronts sorry.