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Leaking manual gearbox! Help needed......

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Old 09-04-2010 | 04:29 PM
  #31  
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DS= driver's side.

Has anyone ever been into this transmission before?

Once you have the tranny resealed again, I'd pressure wash the case, or spray the hell out of it with brake cleaner. Then when the car's driveable I'd want to see whether you can more clearly ID the source of the leak. Glad it doesn't sound like the front seal.

What does your oil pan gasket and your front engine main seal look like? I can believe that you'd have that much oil on the gearbox from a split or leaking breather, but it could also be from engine oil loss that's blowing back onto the tranny. Does the engine consume much oil?
Old 09-04-2010 | 04:58 PM
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I was wondering about a potential gusher of a leak from the drivers side axle flange. Not that I've ever heard of such a thing.

Is it axle grease slinging out of a broken CV boot?

Oil or power steeering fluid from the front?
Old 09-04-2010 | 05:25 PM
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Originally Posted by Rob Edwards
DS= driver's side.

Has anyone ever been into this transmission before?

Once you have the tranny resealed again, I'd pressure wash the case, or spray the hell out of it with brake cleaner. Then when the car's driveable I'd want to see whether you can more clearly ID the source of the leak. Glad it doesn't sound like the front seal.

What does your oil pan gasket and your front engine main seal look like? I can believe that you'd have that much oil on the gearbox from a split or leaking breather, but it could also be from engine oil loss that's blowing back onto the tranny. Does the engine consume much oil?
Dont know about the transmission. Bought the car with 120000k and now its 147000k. But today when I washed the lid I saw some hand writing on it that said G28.55. xxx something so maybe its a replacement.

Just started pulling the tranny out and will try and change most of the gaskets and sealings before putting it back.

Changed the oilpangasket a few weeks ago and now its completely dry. Not a drop of oil from the pan. On the torque tube there is oil from the gearbox and about 1 meter to the front and from there up to the engine, the torque tube and everything else is completely dry. Dont even know where the front engine main seal is but since there are no oil in the front it shouldn´t be a problem or...?

The engine is taking some oil but I mostly drive it on tracks and it doesen´t consume more oil than other 928 racers that I know of.
Old 09-04-2010 | 05:28 PM
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Originally Posted by Landseer
I was wondering about a potential gusher of a leak from the drivers side axle flange. Not that I've ever heard of such a thing.

Is it axle grease slinging out of a broken CV boot?

Oil or power steeering fluid from the front?
The axle flange and the boot are ok and dry from oil.

Noticed that I lack a bit of power steering fluid but its all dry up front so it shouldn´t be from there.
Old 09-04-2010 | 06:08 PM
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Originally Posted by Landseer

There may be reverse switch that is broken and leaking, also, take a hard look. Also front seal where shifter rod enters box. Good pictures will help the other good mechanics here give you ideas.
Should have followed your advice sooner. Just pulled the boot and wires of the reverse switch and the boot was almost full of oil!!

Is it a consequence of the leak or is it the leaking part? Could really a broken reverse switch lose this amount of oil?

Can I just remove it without any consequence on the inside of the box and replace it or will anything happen? Is it possible to see on the switch that it is broken?

Many questions from me to you fantastic rennlisters!
Old 09-04-2010 | 06:56 PM
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Its out and here is how it looks:

Edit: Just noticed its oil inside the switch! Then theres a possibility it leaks right trough....?
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Last edited by Thoomas; 09-04-2010 at 07:28 PM.
Old 09-04-2010 | 09:50 PM
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Oil inside switch is normal but it should not come out from two round wire connectors.

Hope you have small piece which goes into switch on hand. Its easy to loose it.
Old 09-05-2010 | 08:30 AM
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Originally Posted by Vilhuer
Oil inside switch is normal but it should not come out from two round wire connectors.

Hope you have small piece which goes into switch on hand. Its easy to loose it.
The small piece is secured.

Can the oil come out from the wire connectors if the switch is broken?
Old 09-05-2010 | 09:08 AM
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Not sure.
But a leak from somewhere above will fill the boot.

The nice thing about the reverse switch is its relative accessability
Old 09-05-2010 | 09:54 AM
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The switch has two possible ways of leakning, either the sealing ring or from inside. Anyone think the sealing ring looks fishy?

Maybe I can test the switch with air pressure to see if it leaks or will I for sure break it then?
Old 09-05-2010 | 01:28 PM
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Its doubtful sealing ring can leak that much that it would explain all the mess in pics.

Sensor can at least in theory leak though from connector area. Using some air pressure should be ok. Though I would look leak from elsewhere as its so large sensor isn't probably where its coming from. Either selector shaft seal or top cover gasket is more likely source.
Old 09-06-2010 | 12:36 PM
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Sensor can at least in theory leak though from connector area. Using some air pressure should be ok. Though I would look leak from elsewhere as its so large sensor isn't probably where its coming from. Either selector shaft seal or top cover gasket is more likely source.

I tried the switch with air pressure but couldn´t see any sign of a leak. Do you think that the top cover gasket, when you see it in the pictures, could leak that much?

Managed to replace the gasket but I think I´ll try to get the gearbox out of the car to examin it closer. When I get it on the ground and I can get it at an angle to see if it leaks anywhere.

I have the gearshaft, driveshafts and the transaxle left to detach. Any good advice on those things?
Old 09-06-2010 | 01:21 PM
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Search a bit, lots of done it.

I put mine back in yesterday, 84 USA 5 speed.



Drop exhaust
Unbolt inner axles
Break free and slightly loosen 6 TT bolts loose at trans.
Remove rear coupler and shaft spline bolt
Chain-up trans to sway bar.
Unbolt calipers and hang inside fender wells (keep hydraulics connected)
Remove e-brake cable from body
Unbolt shocks in hatch area
Support, unbolt and lower X-member w/ hubs and axles.
Support trans (be sure its completely under control, no ability to roll side-to-side on a trans jack)
Remove the six TT bolts and CAREFULLY remove from TT. Exert NO lateral force on trans input shaft.
Old 09-06-2010 | 02:30 PM
  #44  
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Originally Posted by Landseer
Search a bit, lots of done it.

I put mine back in yesterday, 84 USA 5 speed.



Drop exhaust
Unbolt inner axles
Break free and slightly loosen 6 TT bolts loose at trans.
Remove rear coupler and shaft spline bolt
Chain-up trans to sway bar.
Unbolt calipers and hang inside fender wells (keep hydraulics connected)
Remove e-brake cable from body
Unbolt shocks in hatch area
Support, unbolt and lower X-member w/ hubs and axles.
Support trans (be sure its completely under control, no ability to roll side-to-side on a trans jack)
Remove the six TT bolts and CAREFULLY remove from TT. Exert NO lateral force on trans input shaft.
Thanks for the instruction!

Is there 6 torque tube bolts? I can only se 4?

Anyone know were it is the easiest to lossen the PSD hydralics?
Old 09-06-2010 | 02:57 PM
  #45  
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Definitely 6 TT bolts, here are the 4 on top:




Easiest place to undo the PSD is the junction of the hardline above the muffler and the rubber hose with the 90o bend, on the left side of the tranny. Junction is actaully just off the upper left corner of this pic. The hardline is held to the body by a rectangular bracket. It'll drip for a long time after you undo it, be ready to collect the drips.

Apologies for the filth, that has since been rectified...



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