Final drive question.
Thread Starter
Nordschleife Master
Joined: Aug 2002
Posts: 9,010
Likes: 2
From: South Texas
One of the reasons I'm asking is my final dive isn't looking exactly the way I want it to.
Somehow, the bolts that hold the drivers side bearing cap got loose. Loose enough to allow oil to leak out. I don't know how, or when. This allows the cv joint on eighter side to move into, or out of the drive unit.
I have retightened the bolts, but I'm afraid the dammage has already been done. I'm afraid the movement has put the ring out of alignment with the pinion for long enough that they're permently, fataly, worn. I'm also afraid the movement has permently dammaged the bearings to the two shafts.
The odd thing is I haven't heard any funny noises. I have very good ears, and I listen alought, so that realy suprises me.
The other distressing thing is I can't pull the filler plug off the unit. I broke a SAE grade 9 bolt trying. I was useing a grade 9 bolt with a 17mm head, and I put enough force on I twisted it into. First I didn't know I was that strong, second, I didn't think the plug would resist that kind of force. As such, I can't check the fluid level, or even check the magnetic plug for "hair". Question, would the magnetic drain plug get metal scraps from the final drive?
Anyways, I'm guessing that I'm going to need to rebuild the transmittion and final drive sometime soon. I'm not looking foward to that.
Suggestions?
Somehow, the bolts that hold the drivers side bearing cap got loose. Loose enough to allow oil to leak out. I don't know how, or when. This allows the cv joint on eighter side to move into, or out of the drive unit.
I have retightened the bolts, but I'm afraid the dammage has already been done. I'm afraid the movement has put the ring out of alignment with the pinion for long enough that they're permently, fataly, worn. I'm also afraid the movement has permently dammaged the bearings to the two shafts.
The odd thing is I haven't heard any funny noises. I have very good ears, and I listen alought, so that realy suprises me.
The other distressing thing is I can't pull the filler plug off the unit. I broke a SAE grade 9 bolt trying. I was useing a grade 9 bolt with a 17mm head, and I put enough force on I twisted it into. First I didn't know I was that strong, second, I didn't think the plug would resist that kind of force. As such, I can't check the fluid level, or even check the magnetic plug for "hair". Question, would the magnetic drain plug get metal scraps from the final drive?
Anyways, I'm guessing that I'm going to need to rebuild the transmittion and final drive sometime soon. I'm not looking foward to that.
Suggestions?
Three Wheelin'
Joined: May 2001
Posts: 1,641
Likes: 0
From: Hudson Valley NY
78 to 84 should fit as a matched set. The ring and pinion gear are machined as a matched set. On a manual transmission the pinion gear is part of the main shaft, one piece. You would have to totally disassemble the transmission to change the pinion, then set the pinion depth and ring gear back lash. Not easy to do.
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Thread Starter
Nordschleife Master
Joined: Aug 2002
Posts: 9,010
Likes: 2
From: South Texas
Another weird thing.
The cv joints will move into and out of the final drive slightly, but not side to side. I would have thought a worn bearing would have allowed it to move side to side as well.
The cv joints will move into and out of the final drive slightly, but not side to side. I would have thought a worn bearing would have allowed it to move side to side as well.
Instructor
Joined: Jun 2001
Posts: 209
Likes: 0
From: Ashburn, VA
CV joints have quite a bit of in-and-out play by design. They have to stretch and shrink to compensate for movement of the rear suspension during cornering. They should not have any side-to-side play.
Maybe I missed an earlier post or don't understand you fully, but it sounds normal to me.
Maybe I missed an earlier post or don't understand you fully, but it sounds normal to me.
Thread Starter
Nordschleife Master
Joined: Aug 2002
Posts: 9,010
Likes: 2
From: South Texas
I know the shaft out of the CV joint is suppost to move in and out. However, I did not know the shaft between the final drive and the CV joint is suppost to move in or out.
However, I'm not 100% sure how the unit is put together. The looking at the WSM, I'm not sure how the cv joints shafts are attached to the gears inside the unit. I guess a little movement would be possible.
I'm realy worryed the races, bearing, and gears have been ruint. Is that the likely result of the drivers side bearing cover comeing lose?
Thanks.
However, I'm not 100% sure how the unit is put together. The looking at the WSM, I'm not sure how the cv joints shafts are attached to the gears inside the unit. I guess a little movement would be possible.
I'm realy worryed the races, bearing, and gears have been ruint. Is that the likely result of the drivers side bearing cover comeing lose?
Thanks.
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Instructor
Joined: Jun 2001
Posts: 209
Likes: 0
From: Ashburn, VA
VU,
Makes more sense now.
The output shaft of the differential is an approximately 100mm shaft with 20mm of splines on the end, with a 5mm groove between the smooth part and the splines. I have my 84 5speed trans apart downstairs - I can get exact measurements after work.
If you have more than 5mm of play, then the splines may have damaged the area bearingl that the smooth part of the shaft roll in. Tonight I will check the effects of spinning only partially engaged
Makes more sense now.
The output shaft of the differential is an approximately 100mm shaft with 20mm of splines on the end, with a 5mm groove between the smooth part and the splines. I have my 84 5speed trans apart downstairs - I can get exact measurements after work.
If you have more than 5mm of play, then the splines may have damaged the area bearingl that the smooth part of the shaft roll in. Tonight I will check the effects of spinning only partially engaged
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Joined: Jun 2001
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From: Ball Ground, GA
If there is no noise, forget about it.
If you can't get the plug out with a proper hex wrench, you can pull the cover and drill the plug out. Replacements are not expensive. That would also allow you to ease your paranoia with a direct examination.
If you can't get the plug out with a proper hex wrench, you can pull the cover and drill the plug out. Replacements are not expensive. That would also allow you to ease your paranoia with a direct examination.