anybody here ever do this mod shown in the video with Dennis from Strictly speed? My main bearing pressed in and out as expected, but wondering if this might be good insurance as the fit will not be as tight when the trans gets hot. Any advice? pitfalls?
https://drive.google.com/drive/u/0/fold ... kwycVc5SDA
captive bolt mod for main bearing
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captive bolt mod for main bearing
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Re: captive bolt mod for main bearing
That positioning, is the job of the nose cone, and 'fit' of the bearing hole.
My guess is that the bolt is to 'patch up' a pounded nose cone face and loose bearing hole.
Correct fix is to sleeve the bearing hole(or a brand new intermediate housing),
and machine the nose cone face, flat
and use a steel thrust plate, to improve the full support around the main bearing-face.
Most brands of thrust plates need to be checked that they will clear
the plastic cage on the 091 bearing(if that is your year trans).
They ideally require the nose cone machining too,
but too much, or not enough,
can allow 'limited', 'over travel' of the shift rails, if the driver or gearstick are brutal.
My guess is that the bolt is to 'patch up' a pounded nose cone face and loose bearing hole.
Correct fix is to sleeve the bearing hole(or a brand new intermediate housing),
and machine the nose cone face, flat
and use a steel thrust plate, to improve the full support around the main bearing-face.
Most brands of thrust plates need to be checked that they will clear
the plastic cage on the 091 bearing(if that is your year trans).
They ideally require the nose cone machining too,
but too much, or not enough,
can allow 'limited', 'over travel' of the shift rails, if the driver or gearstick are brutal.
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Re: captive bolt mod for main bearing
I agree, this is a patch. Seems like the right thing would be to replace the shift housing and use a steel thrust plate if you are beating up shift housings
I have no issues jumping out of gear, I don't see any wear on the nose cone from the bearing slamming into it everytime I shift into 2nd or 4th, and my bearing fit is as expected.
Thanks.
I have no issues jumping out of gear, I don't see any wear on the nose cone from the bearing slamming into it everytime I shift into 2nd or 4th, and my bearing fit is as expected.
Thanks.
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Re: captive bolt mod for main bearing
I prefer the bolt on the flanged bearings over the thrust plate. It lets you use a factory gasket still instead of two layers of silicone to seal the thrust plate.
002 and 091 bearings I prefer Bruce's plate, basically a small plate that bolts on allowing the bolt to have a secure spot and then the plate holds in the bearing as well as the nose cone.
It's nto really a fix for a bad gear carrier as it is extra support and an alternative to a thrust plate. The bolts or thrust plates really help with shock loads and heavy thrusts of drag racing and off roading.
If you're using an 002or 091 bearing application, it's better to use the 002 bearing with the plastic cage locked in place by putting the bearing in backwards. The thrust washer of 4th will then be able to hold in the plastic cage if it wants to pop loose.
002 and 091 bearings I prefer Bruce's plate, basically a small plate that bolts on allowing the bolt to have a secure spot and then the plate holds in the bearing as well as the nose cone.
It's nto really a fix for a bad gear carrier as it is extra support and an alternative to a thrust plate. The bolts or thrust plates really help with shock loads and heavy thrusts of drag racing and off roading.
If you're using an 002or 091 bearing application, it's better to use the 002 bearing with the plastic cage locked in place by putting the bearing in backwards. The thrust washer of 4th will then be able to hold in the plastic cage if it wants to pop loose.
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Re: captive bolt mod for main bearing
That is some solid info. Thanks.
Yeah, I guess I hadn't considered the additional opportunity for a leak using a thrust plate.
Thanks.
Yeah, I guess I hadn't considered the additional opportunity for a leak using a thrust plate.
Thanks.
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Re: captive bolt mod for main bearing
Axial thrust on the bearing isn't just from shifting hard. Every time you get on the throttle, it's pushed into the nose cone. Every time you get off the throttle, it is pulled back into the gear carrier.
The later 002/091s suffer worse since the contact area of the bearing against the nose cone is so much smaller.
I've seen gearboxes built by Kevin at KCR where he drilled and tapped the gear carrier at the bearing, then used a large diameter washer bolted on to hold the bearing down. The few I saw had notches pounded into the washer, so although it helped, it didn't stop it 100%. That is what inspired me to make my plate that Tim mentioned above.
Here's my plate:
https://www.thesamba.com/vw/classifieds ... id=1734074
Can you post the link to the video in your first message?
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Re: captive bolt mod for main bearing
here's a link to the youtube video. You can see the gear carrier he's working on is really loose.
https://youtu.be/lYvOUb5lCWo
I hadn't thought about the thrust load on the throttle, but with helical cut gears that's sure going to happen.
https://youtu.be/lYvOUb5lCWo
I hadn't thought about the thrust load on the throttle, but with helical cut gears that's sure going to happen.