Looking for a little advice here. I'm active on some other boards, but this seems to be the place to go for transmission help, something I have no experience with. For a while now, whenever I give the car some power during a turn, I can hear a vibration. I dropped the pan recently, and found what looked like part of a pin and some non-magnetic shavings.

After doing some research, I'm guessing that one of the pinion gears stuck to the shaft, causing it to spin, breaking the pin. This seems to be a relatively common issue with these trannies? I've never done any burn outs or anything, but snow/ice are issues around here, and I like to take curves fast, so I guess it just happens.

Does this sound reasonable, and if so, what all would be damaged? Can I just replace the pinion gears/shaft/retaining pin and call it a day? If so, where could I find them? I'm over 100K on this car, and the tranny does have some other issues, but I'm trying to keep it alive for a while longer before I have to swap it out.

Thanks for your help.

Edit: forgot to mention, this is a Regal LS, so it's got the screwy 3.05 final drive.

Do you have a pic of the pieces you found in the pan? Without seeing them it could be anything. Differential failures arent real common but they do happen time to time regardless of driving style, though burnouts with non HD differentials put them at risk for failure sooner than others. Often if the diff pin is broken and the cross pin and gears are bad and the cross pin has been spinning in the diff case you will need to replace the whole assembly. Most places wont sell just the differential gears and cross pin so you will need to buy a complete one. You should also check the axles to make sure they arent bad as well as suspension compenents as this can also cause vibrations during a turn. If the metal you found in the pan is non magnetic then it is likely aluminum from the cross pin in the diff grinding away at the inside of the diff cover and you wont really know what you need until you pull the cover off and take a peek inside.

__________________
www.TripleEdgePerformance.com
4T65E Transmission Info
Voted GPF.net Community Hero

Hmm, so I'm probably looking at a new diff, I guess. No pics, unfortunately. I overstated the "shavings" a bit, it was more of a heavy glitter effect on the bottom of the pan, and they weren't attracted to the magnet, so I assumed they were aluminum from the case. Combined with the part of a pin, that's why I was thinking pinion shaft retainer. I'm relatively confident in the suspension components, and the axles seem ok; the vibration starts only after applying a very specific amount of power, and it's one of those that's there or it isn't, there's no varying degrees.

If it comes to replacing the entire diff, I may just baby it for now and replace the whole damn thing next summer, I should have access to a lift by then. I'm also thinking I need a new PCS and possibly a new input clutch piston, so I don't know if it's worth putting the money into this one without doing a complete rebuild, which I don't have time for at this point.

Thanks for your help.

A failing diff is definately not something you want to push off and hope it lasts you until next summer, but again you wont know until you pull the cover. When the diff lets go you loose all movement and because the cross pin will likely burrow a hold all the way through the diff cover you will lose all trans fluid and risk burning up the trans, and when a hole shoots through the case it will be instant and fluid will drain out immediately.

__________________
A.K.A. Trannyman's wife
www.tripleedgeperformance.com
www.tripleedgeperformance.com/4T65E_Parts.php

The more I think about this, the more I think I should just spend the cash and get this thing fixed. A few more questions, then, if you'll indulge me. Since this is my daily driver, a lot of downtime isn't an option, so I'd like to have the parts ready to go when I pull the diff cover, assuming that my diff pin theory sounds plausible/likely.

Is there any other parts that are likely to be damaged? I don't think the pinion shaft would damage the ring gear or anything, but I've been wrong before. Would the output shaft be a problem? I know that it would probably be best to replace the diff cover, but as long as it's not too bad, would it cause a problem to reuse it?

How much fluid should I have on hand? I know a pan drop is ~7.5 qt, so I assume removing the diff and side cover will be closer to 10? More?

I know that the 3.05 diffs aren't anywhere near as common as the 3.29s, will it be a problem getting a used, inspected one, say from a supplier like TripleEdge?