Help - Unwanted "gift" found inside 915 gearbox

[rob justice]

Since the engine and gearbox have be sitting for 4 years. I deceided to change the gearbox oil tonight. Unfortunetly when removing the drain plug, along with the usual 'fuzz' I discovered the following.
Please note the gearbox shifts very well indeed once warm and had no reason to suspect anything was wrong apart from a minor whine in all gears.
The box has covered 71k miles in an '85 Carrera 3.2.
Anyone has any thoughts on wether to remove and strip ASAP or hold off till the winter.
Any thought would be appreciated.
Best regards
Rob

[Jgordon]

Looks like a retainer clip of some kind. I'm no expert though.

[Blanco]

I also have a worn and tired tranny... I changed the fluids early this year and luckly nothing metal came out.

Keep your eye on the classifieds as there is one that is rebuilt for ~$1000 dollars.

This might save you time and money.

[rob justice]

I've had a good look through the manual and cannot see anything resembling what came out!
Thing is it's still shifting perfectly. If I lost a gear then it would be a starter.
Hope to keep it running (though not in daily use) until winter then strip it out and get it rebuilt.

[johnsjmc]

I think it looks like part of a bearing cage. You are taking a big chance when any large pieces of metal are circulating in a trans If a piece gets between a pair of gears the results are often very expensive.

[MichiganMat]

if you tear it down and need parts, I have 915 trans parts for sale here:

http://forums.pelicanparts.com/porsche-911-used-parts-sale-wanted/233699-915-trans-gears-recaro-mount-slider-fiberglass-sc-rockers-more.html#post2047789

[1972_911T]

looks like parts of one of these to me!





THRUST BLOCK/ENERGISER What ever one of those is!

[rob justice]

I reckon its part of the outer cage of a bearing - the maximum thickness is approx 0.5mm - my thoughts are thats it off the road until fixed. If something big goes - it could be very bad indeed. I've no confidence in the car in its present state.

[Tyson Schmidt]

Looks like a carrier bearing cage.

If it were a thrust block, you'd definitely be having shifting issues!


The good news is that you only have to pull the axle flanges and diff side cover off to replace the carrier bearings.

[john walker's workshop]

cage bits for sure. there are also 4 others on the main and pinion shafts.

[rob justice]

Tyson
Cheers for that - its possibly cheered me up a little. Think you could be right because the gearbox changes well but whines in all gears slightly at low revs during acceleration - its noticable but not loud.
I would need to split the driveshafts from the axle flanges and then remove the axle flanges from the diff casing. Reckon this would be a good starter before removing engine and gearbox if nothing can be found on the diff.

[Nine9six]

Rob,
You will want to drop the motor and trans together...Yes, removing the axle shafts is a start. Remove wheels, calipers, rotors, and main hub nut (you may need heat on this nut), as it is torqued to 2xx ft lbs. remove the six bolts that hold each axle shaft to the trans. The flex of the inner and outer CV joint will allow you to pull the axle shafts away from the trans and out of the trailing arms.

[Tyson Schmidt]

Well, you can actually do this in the car, if you want to save time. You'd only need to disconnect the inner cv's from the axle flanges, remove the axle flanges, then pull the sidecover. The diff will then practically fall out.

Then pop the races out of the side cover and diff housing. You'll need a special puller to remove the bearings. You could take it to a shop and have them remove them for you. Make sure you don't lose any shims, or swap them. It's very critical for side load.

[rob justice]

Just had a look at the gearbox - side with the gearbox oil cooler has the large bolt on diff cover, the other dosen't.
Would the diff have to be removed to change the bearing on this side if its the faulty one?
Nine9six - I was hoping to just remove the 6 axle shaft bolts and tie the driveshafts up out of the way rather than remove completely

[johnsjmc]

You remove the large bolt on cover to remove the Diff The bearings are pressed on each end of the centre section when removed. I don,t think the oil circulation path from the diff is open enough to move bearing parts to the drain plug as easily as the bearings on the main shaft . They sit right above the plug. I think opening it up completely is the best option as trash can/will be everywhere already.

[Tyson Schmidt]

Originally posted by rob justice
Just had a look at the gearbox - side with the gearbox oil cooler has the large bolt on diff cover, the other dosen't.
Would the diff have to be removed to change the bearing on this side if its the faulty one?
Nine9six - I was hoping to just remove the 6 axle shaft bolts and tie the driveshafts up out of the way rather than remove completely

Once you remove the side cover, the whole diff comes out. The bearings are pressed onto the diff. You can do both this way.

Sounds like you have a Euro model with the trans cooler. Make sure you remove the pick-up screen for the pump, and clean everything out really well. It would be a good idea to remove the plate under the front of the trans that has 4 nuts holding it on, so you can check for debris in the gearbox section.

[rob justice]

Once the diff side cover is removed, the diff is completely free to lift out or is there anything else holding it in.
Sorry for the questions but the section on the Diff in the Bentley manual is almost non-existant, only describes how to remove the output seals.

[Wayne 962]

Yum, those tranny coolers are worth big coin! Sell the cooler (you don't need it if you don't race), and then use the $$$ to rebuild the tranny!

-Wayne

[rob justice]

Just been through to Porsche dealership - Mechanic of whom I spoke too was not up to working on old type 915 boxes!!!
I reckon thats its definatly part of the bearing cage that I've found and going by the diameter of the bearing - it looks as if its a fair size of which again points me to one the diff bearings.

[rob justice]

One concern I have is checking the clearances upon re-assembling the diff. Is it good practice to check these clearances on 911's or just ensure the shims are correctly re-installed after fitting new bearings and putting it all back together.
Only experience I have on diffs is on old Escorts with crown gears that always needed shimed/adjusted even after just stripping.