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Posted by: JOHNMAN Feb 13 2006, 11:45 AM

I am about to fabricate some rear shift linkages for some -6 conversions, and have been seeing a slight bend in the rear shift rod.

When I did the conversion 13+ years ago, it was common(?) for the shift rod to be absolutely straight as is confirmed by my existing shift rod. We purchased the straight rod from a vendor in CA 13 or 14 years ago possibly from Galen Bieker and it has worked well for both the original 901 side-shifter as well as the current 915 (vellios) transmission.

My main questions are:

1. Is there a need for the shift rod to have a slight bend?
2. Does the slight bend help minimize binding in the bushings?
3. Is the bend to avoid bumping into the bottom of the engine case?
4. What is the location of the slight bend(s)?
5. Is there 2 slight bends or is there just one?

Pics would be very helpful.

Otherwise, I'll continue to make up straight ones and verify that they work with my existing 914-6 conversion.

Thanks for your input.

Posted by: john rogers Feb 13 2006, 11:58 AM

When I did my conversion I had to put a slight bend in the rear rod section. This was to clear the case. I used one of the aircraft type couplers so there was less free play at the front and stock type bushing at the rear.

Posted by: trekkor Feb 13 2006, 12:05 PM

Back when I did mine, the first thing I noticed is that the stock shift rod for the FOUR is *very* bent. I works fine very bent.

I just cut mine at both ends and rotated the bend downward to clear the headers. Something like 60 degrees IIRC.

The shifting action feels exactly the same.

here's a couple of pics:


KT


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Posted by: Mueller Feb 13 2006, 12:05 PM

I thought it was the motor mount that also had a bearing on whether straight or bent???

Posted by: trekkor Feb 13 2006, 12:12 PM

The motor mount is directly above the shift linkage tunnel exit. No interferance.

People have said the bend looks outrageous, it's the same ol' bend.

Another pic:


KT


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Posted by: Mueller Feb 13 2006, 12:14 PM

QUOTE (trekkor @ Feb 13 2006, 11:12 AM)

The motor mount is directly above the shift linkage tunnel exit. No interferance. People have said the bend looks outrageous, it's the same ol' bend. Another pic: KT

what about the "quick-six" mounts??

Posted by: trekkor Feb 13 2006, 12:28 PM

If you are referring to the Patrick mount, that's what I use.
I believe the "Quick Six" is offered by Motor Miester and I haven't seen that one.


KT

Posted by: JOHNMAN Feb 13 2006, 12:43 PM

KT,

Which headers are you using?

Posted by: trekkor Feb 13 2006, 12:54 PM

MSDS headers.

Martin Schneider, MSDS, inc

http://www.msdsinc.com

I really like them and they sound great.

KT

Posted by: brant Feb 13 2006, 02:33 PM

Trekkor,

taking the bend out as much as possible, is theoretically better because there is less chance for the rod to flex.

Theoretically you could also make a lighter rod (lighter material) because it would not have to be as strong of material in order to be flex free since straight is a stronger shape than bent.

that may all be just theory and not matter in real life.
but we made ours straight with very light weight (thin-walled) stock to try and take advantage of this.

Regarding the original question.
tiny... barely perceptable bend in the final 6 inches of the rod. Helps free up travel through the bushing in the side shifter console.

brant

Posted by: trekkor Feb 13 2006, 05:05 PM

Nearly all 914's use a shift rod this bent.
I don't think they flex.

Sorry, I should have just let it go...


KT

Posted by: brant Feb 13 2006, 05:14 PM

The original -6 rod is not bent... and some say its better.

Its only theory...
pretty much impossible to prove
I did it because our race shop said that it was less flexible on the BIG time track cars they build.

I reality its impossible to prove, but every little thing helps.

brant

Posted by: 736conver Feb 13 2006, 05:22 PM

No scientific data here, but I made my shift rod straight for my 3.2 conversion.

Posted by: JOHNMAN Feb 13 2006, 11:28 PM

So I have a couple for straight (me and 736conver) and I have a couple for slight (or more) bent.

The one that PMS pushes (and we didn't use and he wouldn't take back) has a slight bend about 6" from the front (firewall) end. James uses a steering shaft universal joint at the firewall (which we again did not use as there was no provision to install the dust boot). I think that the slight bend is to simply clear the engine case.

I do recall that I did some slight grinding on the bottom of our case when I installed my straight shift rod many years ago. Perhaps if the engine and trans were not bolted solidly into the chassis, I would need a bend as the engine would move around.....

I think I'm going to make mine straight. I could always put a slight bend in it if needed.

Posted by: RON S. Feb 14 2006, 06:15 AM

John,


I made mine straight,it seemed the simplest way to keep it simple.


The tube is 4140 I got from Mcmaster,and i Apex coupling up front.It seems to work just fine.

Heres 3 pics to show.

Ron


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Posted by: RON S. Feb 14 2006, 06:19 AM

#2



center section


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Posted by: RON S. Feb 14 2006, 06:24 AM

Last one,


Tail section,

Ron


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Posted by: 9146986 Feb 14 2006, 07:00 AM

I've been making conversion shift rods for the last eight years on a jig I built specifically for the part. I say if you are building these for sale..... go ahead and make them straight .......

Seriously, if you measure the shift rod connection points, from the centerline of the car, you'll get your answer.

Posted by: Dr Evil Feb 14 2006, 11:38 AM

I had mine bent by Dan Root because it was recommended. Shifts fine (for a car of jack stands)

Posted by: JOHNMAN Feb 14 2006, 01:05 PM

I started out and made a jig from an original shift rod and tried several (about 5) other original shift rods. Each of the shift rods were slightly different. Only 2 fit nicely in the jig.

There is some offset between the ends of a stock 4-cyl side shift bar (which is why I asked the question in the first place).

I ended up taking my known to work (for the last 13-14 years) shift rod (straight) out of the converted car and made a jig from it instead.


I may try some slight bends to see if they make any difference since nobody seems to know a definitive answer.

Posted by: 9146986 Feb 14 2006, 01:47 PM

OK, OK! Since I don't have the original measurements I've used to make my jig, which was longer ago than I remember, more like 10 yrs. If I remember correctly there's about 1 1/8" offset from the shifter bushing boss in the firewall to the console on the transmission. So YES, you do want bends in the shift rod to account for this offset. If you don't have bends in it, the firewall bushing acts like a fulcrum and forces the linkage over to the side, and makes it harder to engage the reverse/1st gate.

Posted by: dimitri Feb 15 2006, 03:16 PM

Looking at my original 914-6 and the 74 6 conversion, both with later
side shifter transmissions and stock original heat exchangers, the shift rod
has to be straightened with this combination of parts, because the heater
section of the 914-6 reaches right up under the oill return tubes. This
makes it necessary to run the shift rod on top of the heat exchanger. On the
other hand if your exhaust system does not reach into this area and when
attached to the engine you have a clear view/path from the exit on the firewall to the shift point, rebending is not necessary. Dimitri

Posted by: porschetub Oct 31 2016, 12:03 AM

My shifter rod had a bend around 150 mm from the end of the gearbox shifting was ok then worse ,I know my 911 mounts are shit and have gone soft,removed the rod and the end literally fell of due to a crappy brazed weld.
New mounts on the way and plan to deal to the rod,don't think my gearbox can handle to many more bad shifts .
Maybe I will pm Perry for his master plan?,I don't think straight is right for a sideshifter.

Posted by: gereed75 Oct 31 2016, 06:42 AM

I believe it is straight but optimally will need a second joint in the back to eliminate any binding as it enters the shift console.

Take a look at the tangerine shift kit.

Posted by: gandalf_025 Oct 31 2016, 01:47 PM

I know you are talking side shifter..
but here is an original 6 tail shift rod that was
cut to use in a car with an early 1965 engine.

Pretty serious mod, but it shifted fine.

Posted by: SirAndy Oct 31 2016, 01:51 PM

Holy thread necromancer!



Also, whatever you do, just make sure the start and end of the rod are in the same plane.

If they aren't you'll get binding ...

Posted by: jim912928 Oct 31 2016, 02:38 PM

I didn't have to modify mine at all. 75 914, Rick Johnson mount, 3.2l, stock 901 side shift.

Posted by: horizontally-opposed Oct 31 2016, 03:28 PM

Have a 73 side-shift car with a 2.2 six.

John Holleran, who did the conversion and has done a dozen or so, mentioned he built the shift rod by using the forward shaft from a 911 (the one that goes into the interior) and the back of a 914 shift rod. It looks straight to these eyes, and the welding is beautiful.

I was worried about the shifting, as my 914 was one of the better shifting 901s I had tried (or more likely just familiar). It shifts better now than it did.

YMMV!

Posted by: altitude411 Oct 31 2016, 04:29 PM

Well it is Halloween.

Posted by: porschetub Nov 1 2016, 07:36 PM

Jim not really answering the original question ,please share ,straight of offset bend?some need to know including me,thanks

Posted by: jim912928 Nov 1 2016, 08:53 PM

stock bend...non-modified from my 75...shifts perfect with no interference with heat exchangers.

Posted by: Mark Henry Nov 1 2016, 09:40 PM

My rod is straight...but I did a Marky do copy roo....sort of like a tangerine.
In other words because I'm a cheap ass so I copied it from a pic.

Posted by: mb911 Nov 2 2016, 05:00 AM

I don't remember modding my last 6 conversion.. I already powdercoated mine in prep for the new install..

Posted by: mlindner Nov 2 2016, 07:47 AM

I'm still working on my conversion and this has been in the back of my mine...I'm going to build a jig. Does anyone has a extra side shifting rod I can cut up to help the process, will pay shipping. If so, and you like the end results I will modify yours at no charge. Best, Mark

Posted by: rgalla9146 Nov 10 2016, 09:14 AM

This is what I did.
It's an assembly of four pieces.
I used the front and rear of a side shift rod with
a length of rear shift grafted into the middle. Done in a fabed' jig.
This is for a 6 conversion with stock heat exchangers.
I used the curved sections of the rear shift rod to create an offset to clear the HEs.
I'll do the same for the 915 installation which has a 916 replica side shift mechanism.


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