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914World.com _ 914World Garage _ first gear replacement
Posted by: zeezee Feb 21 2009, 06:12 PM
First is gone ... grinds going in, pops out when I let the clutch out.
I've done lots of linkage adjustments, replacements, etc. etc.
Followed the Pelican Tech article to open the tranny and check out the gears.
This is what I see...
dog tooth:
slider:
I'm assuming I'll be replacing the syncro ring, and the dog tooth gear.
And the slider is still ok. Yes? No?
Any recommendations on where to pick up the parts?
Posted by: Joe Sharp Feb 21 2009, 07:06 PM
I think you can find a slider for just under $400. Sorry to tell you that but that is reality. I posted some pictures of a new one once, it was colser and crisper than your pics. If you can find them maybe you can deside if it worth the money.
Posted by: J P Stein Feb 21 2009, 07:20 PM
I'll sell ya a first gear with good dogs & syncros for 100 bucks. Your slider looks remarkably good considering the condition of those dog teeth. Considering the price of a new slider ( if you can find one), I'd get out some files and work on that thing.
Posted by: Jeff Bowlsby Feb 21 2009, 07:37 PM
Yay Alan! 
Posted by: zeezee Feb 21 2009, 08:46 PM
Yay Alan!
Thanks Jeff. But putting it all back together w/o leaks is the true test.
Posted by: toon1 Feb 21 2009, 09:41 PM
The back end of the tranny's are not that bad for leaks. Make sure everything is clean and use a good sealer like yamabond or red permatex (565 I think)
Posted by: Jeff Bowlsby Feb 21 2009, 10:19 PM
The factory gasket is better and cheaper than a tube-a-goo...and you can get the end cap off next time....
The back end of the tranny's are not that bad for leaks. Make sure everything is clean and use a good sealer like yamabond or red permatex (565 I think)
Posted by: Dr Evil Feb 22 2009, 01:07 AM
Your slider is remarkably in good shape. You can get a way with reusing it. I can send you a used 2-5 set of teeth that you can use in 1st or you can buy a new 1st set of teeth. I also have some good used synchro bands. You are lucky with that slider.
Posted by: toon1 Feb 22 2009, 10:30 AM
The factory gasket is better and cheaper than a tube-a-goo...and you can get the end cap off next time....
The back end of the tranny's are not that bad for leaks. Make sure everything is clean and use a good sealer like yamabond or red permatex (565 I think)
Guess I should have clarified.
I use both, when using the sealer, I go very light, just enough to make a seal but not to squish it into the case. The permatex red is anarobic so it comes apart with no problems.
Posted by: Cap'n Krusty Feb 22 2009, 10:38 AM
You DO NOT need any sealer on the nose cover gasket. The Cap'n
Posted by: Dr Evil Feb 22 2009, 10:43 AM
Sealer use on the transmission is verboten! No, no, no!
Posted by: zeezee Feb 22 2009, 10:47 AM
On mine - both the end cap and the intermediate just had goo - (white - looks&feels like silicon) - no cork-type gasket.
It worked fine - no leaks.
While knocking the end cap off, the intermediate slid out a bit too.
So, do I need to re-goo the intermediate? Or will it seal?
----
Thanks Dr.Evil for the opinion on the slider - you made my day.
Posted by: zeezee Feb 22 2009, 10:50 AM
On mine - both the end cap and the intermediate just had goo - (white - looks&feels like silicon) - no cork-type gasket.
It worked fine - no leaks.
While knocking the end cap off, the intermediate slid out a bit too.
So, do I need to re-goo the intermediate? Or will it seal?
----
Thanks Dr.Evil for the opinion on the slider - you made my day.
OK - odd timing w/Dr. Evil there.
So can I put a cork gasket on the intermediate without dropping the tranny?
Posted by: J P Stein Feb 22 2009, 11:26 AM
The gasket (paper) between the intermediate plate & the case sets the pinion depth. The gaskets come in 2 thicknesses.....010 & .005" (round numbers in inches). Should the gasket be replaced, always use the same thickness as what is in there. Pulling the gear stack with the trans in the car is "a bridge too far" for me.....getting it back in, actually.
Posted by: Dr Evil Feb 22 2009, 12:23 PM
No cork, only paper. They come in various sizes from .009" to .022". Generally you can make the right thickness with the gaskets provided in the kit as there are 3 of them. I have plenty of case to intermediate plate gaskets, but no intermediate plate to tail cone gaskets as those get used up in every build and you can not buy them separately. IF you MUST pull the tail cone, AND you dont want to buy a whole seal kit to get the gasket for it, THEN you CAN use some sealant. It is not a precision fit so the dimension is not a big deal. Having the paper gasket separating in front of the intermediate plate is not a big deal. Just reassemble things and it should not leak, UNLESS it was assembled with goop before. If goop was used you might as well pull the stack and replace the seals after cleaning the surfaces. Otherwise, you risk having leaks, and pinion misalignment.
Posted by: toon1 Feb 22 2009, 03:38 PM
You DO NOT need any sealer on the nose cover gasket. The Cap'n
Sealer use on the transmission is verboten! No, no, no!
I have it on mine with no issues.
whats' the reason not too?
Posted by: Dr Evil Feb 22 2009, 05:04 PM
Reasons:
1- it is unnecessary, the paper seals have held their own for 30 or so years with no sealant.
2- it is a potential for tolerance goof ups
3- it can get into places where it should not be
Posted by: PRS914-6 Feb 22 2009, 05:43 PM
I'm going to disagree with the others. Replace the slider. It has taken a beating and burred over. No way to measure the wear and could easily ruin the new syncro and you'll be right back at it again. I do however error on the safe side.
I once pulled a 901 out 3 times because it wouldn't shift into first correctly. It had a slider that "looked" perfect but was too worn to operate correctly.
You never regret doing it right.....
Posted by: Dr Evil Feb 22 2009, 05:53 PM
With a good band and teeth, I have never had issues using sliders in that shape. I advise the owner of their options, of course, but the $500 price tag tends to make most open to using good used parts.
Posted by: PRS914-6 Feb 22 2009, 06:03 PM
With a good band and teeth, I have never had issues using sliders in that shape. I advise the owner of their options, of course, but the $500 price tag tends to make most open to using good used parts.
And I totally agree with you. I just don't think that's a very good used part. Try calling Carquip and ask for Tom for a good used one or hell I have bought decent used trannies for $100.00 to get a few parts.
Posted by: Dr Evil Feb 22 2009, 06:05 PM
In the 100+ boxes I have repaired or parted I have found about 4-5 usable 1st sliders.
I wonder what carquip charges for a good used one. I am going to be selling them a load of parts here shortly and will ask.
Posted by: PRS914-6 Feb 22 2009, 06:25 PM
Ask for Tom and tell him we talked. He's a pretty upfront guy and treated me REAL good when I built my custom geared 915. We spent a bunch of time working out gear ratios. Those that have been in my car know the gearing turned out near perfect thanks to Tom's help. I also sold him several trannies. I wanted a mid section of a 915 that I could cut a large section out of for shift fork testing and he sent me one for free! He was fair on both the buying and selling. My experience anyway and nothing but nice things to say.....Hopefully he treats you guys as well.
Posted by: Dr Evil Feb 22 2009, 08:12 PM
I have talked to Tom many times. He is always straight forward.
Posted by: J P Stein Feb 22 2009, 09:43 PM
These burrs and any others like them need to be filed smooth or they will hang up on the brake bands.
My photo chop work sux, but you get the idea.
Good pix, BTW. My freaking camera can't do that....or we have operator error.
Attached image(s)
Posted by: PRS914-6 Feb 22 2009, 11:05 PM
This is what I look for.....
1. Arrow pointing towards tips.... They should be distinctively sharp, not dull and not worn down at all and be without burrs. Any heat discoloration is cause for trash
2. Circle area should not be worn or it slides over the syncro too far before performing its function. You need a good one to see how far it moves before touching the syncro, it's not very far. This area typically wears a lot but may still look perfect.
3. The parallel lines.....There is a distinct shape to the inside of the slider. You need a good one to truly see how distinct it is. It should not show signs of wear. When #2 wears the shape is no longer distinct.
4. The shift fork should not be loose in the outside groove but it's the forks that typically wear if someone has been leaning on the shifter but I have seen the groove wear too.
The area that slides over the dog teeth looks worn too me (between the teeth) but can't tell by the pic
Posted by: Jeff Bowlsby Feb 24 2009, 08:26 AM
I know I have bought the rear cover gaskets separately, I assume they are still available. PET says its is PN 901.301.392.12
Its $3.25 from the Bird...
No cork, only paper. They come in various sizes from .009" to .022". Generally you can make the right thickness with the gaskets provided in the kit as there are 3 of them. I have plenty of case to intermediate plate gaskets, but no intermediate plate to tail cone gaskets as those get used up in every build and you can not buy them separately. IF you MUST pull the tail cone, AND you dont want to buy a whole seal kit to get the gasket for it, THEN you CAN use some sealant. It is not a precision fit so the dimension is not a big deal. Having the paper gasket separating in front of the intermediate plate is not a big deal. Just reassemble things and it should not leak, UNLESS it was assembled with goop before. If goop was used you might as well pull the stack and replace the seals after cleaning the surfaces. Otherwise, you risk having leaks, and pinion misalignment.
Posted by: zeezee Feb 24 2009, 12:52 PM
I know I have bought the rear cover gaskets separately, I assume they are still available. PET says its is PN 901.301.392.12
Its $3.25 from the Bird...
Rats - out of stock at the bird. And AA has a $25 minimum.
I ordered the whole gasket kit from someplace else.
Thanks for looking!
Posted by: Dr Evil Feb 24 2009, 03:15 PM
Ya, the bird has been out of stock on them for a long time. I didnt even know they still offered them.
I could have gotten you a seal kit for a little over the $25.....
Posted by: zeezee Feb 25 2009, 03:58 PM
Ya, the bird has been out of stock on them for a long time. I didnt even know they still offered them.
I could have gotten you a seal kit for a little over the $25.....
double rats.
I had read previous posts from you - you said you didn't have any of the singles. I must have mentally crossed you off the kit list too.
Posted by: zeezee Mar 8 2009, 01:03 PM
I replaced the dogs and the syncro. Put it all together. Got about 10 good 1st gear shifts out of it. No grinding or anything. Then it was back to popping out of first when I let the clutch out. 
I took it apart again. The dogs haven't changed. So I guess I need to replace the slider ... 
Why would it work a few times then stop like this?
I guess my options are getting one from Pelican or AA... any other suggestions?
... sigh ...
Posted by: Dr Evil Mar 8 2009, 04:04 PM
OK, popping out means that either the groove in the slider is flattened, the synchro band does not have enough spring tension, or that the band and blocks have a problem.
From your pic it looks like the synchro band retaining groove is adequate, but its a pic and I can only deduce so much from it. I would be happy to inspect your slider and see if I have a cheaper replacement used one that is in better shape if yours turns out to be poo. Or, I can jsut look at it for you and give you my opinion 
Posted by: Joe Ricard Mar 8 2009, 04:32 PM
Or the shift console fingers are not pushing the 1st gear shift rod completely into gear. Little bit of wear here or there all adds up to a few thousanths of an inch not enough.
Posted by: Dr Evil Mar 8 2009, 04:53 PM
True that. I was assuming that the external stuff had been addressed as previously prescribed
Posted by: zeezee Mar 8 2009, 08:20 PM
OK - so I put the gears all back together. The fingers feel snug in the slider. Tried measuring the slider-to-1st gear gap - kind of difficult. Came up with .125" to .15"
Is there something more exact I could look at or measure?
Posted by: PRS914-6 Mar 8 2009, 08:46 PM
OK - so I put the gears all back together. The fingers feel snug in the slider. Tried measuring the slider-to-1st gear gap - kind of difficult. Came up with .125" to .15"
Is there something more exact I could look at or measure?
That sounds like way too much. The slider is typically closer than that. Try this......put it in first gear so the shaft is in the detent, loosen the shift fork, push the slider firmly onto first gear and then re-tighten the fork. Now take a look and you will find that it's way closer. Fine tune from there. If the slider is not all the way against the gear when the shaft is in the detent it will pop out of gear all the time.
Goin' by memory.....
The shaft must be in the detent
the slider must move all the way to the gear while shaft is detented and relaxed
It must not rub on the syncro
reverse must properly engage when detented
Posted by: zeezee Mar 8 2009, 09:51 PM
That sounds like way too much. The slider is typically closer than that. Try this......put it in first gear so the shaft is in the detent, loosen the shift fork, push the slider firmly onto first gear and then re-tighten the fork. Now take a look and you will find that it's way closer. Fine tune from there. If the slider is not all the way against the gear when the shaft is in the detent it will pop out of gear all the time.
Goin' by memory.....
The shaft must be in the detent
the slider must move all the way to the gear while shaft is detented and relaxed
It must not rub on the syncro
reverse must properly engage when detented
The fork isn't very adjustable on the shaft. There is a indentation on the shaft for the fork bolt.
Posted by: Dr Evil Mar 8 2009, 10:01 PM
If you remove the bolt, while it is in gear, and are able to push the slider further onto the dog teeth, then you have an adjustment issue. More likely in the linkage than the 1st gear fork shaft.
Posted by: zeezee Mar 8 2009, 10:47 PM
YAY! I was able to adjust the fork so the slider snaps into first. Makes a lot more sense now.
Ah - the finer details of a job you only learn by doing.
Hopefully this didn't adversely affect reverse, but I guess I can't tell until it's all put back together.
I'll let you know in a couple days.
Thanks for the help!
Posted by: PRS914-6 Mar 9 2009, 12:56 AM
The fork isn't very adjustable on the shaft. There is a indentation on the shaft for the fork bolt.
Posted by: zeezee Mar 24 2009, 11:56 AM
It's all back together - and shifts well.
Thanks to everyone for all the great help!
Posted by: Dr Evil Mar 24 2009, 12:10 PM
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