02 Lesabre Roaring noise

[Lesabrelover]

I have an 02 Lesabre with 127K miles with a loud roaring noise coming from the right cv joint/transmission area. I appears to be coming from the part where the right axle joins in to the transmission ( the little bell shaped piece bolted to the transmission that the axle goes in to). It does not seem to be the cv joints as the are dry and no signs of leakage around the boots. I put the car up on jackstands and put it in gear and get the same noise,so it is not a tire causing the problem. Any ideas???

[gbeeley]

Originally Posted by Lesabrelover

I have an 02 Lesabre with 127K miles with a loud roaring noise coming from the right cv joint/transmission area.

Worn CV joints usually don't make that kind of noise... usually clicking or clunking, possibly vibration.

Roar on the passenger side of the tranny - doesn't sound like welcome news. On the driver's side, it could be pump noise from low fluid or air getting into the hydraulic system some other way (such as a broken filter).

A couple of questions:

1. Does the sound change if you only allow one wheel to turn instead of both? And if so, which wheel turning makes the sound worse/better?

2. Have you dropped the transmission pan to look for metal debris?

3. Can you tell if the noise is coming from right inside that 'bell' cover, or is it slightly further inside the transmission? (putting a hose to the ear and to the tranny might help) There are a couple of components inside that cover that can be replaced without disassembling the entire tranny on the 4T65-E (as far as I know).

- GB

[Lesabrelover]

Noise is definitely coming from passenger side. No noise when left side only turns. Fluid is full and bright red. Filter and fluid were replaced at approx 100K miles. Noise seems to be coming from the bell shaped housing that the axle goes into. When you manually rotate the right wheel, you can hear an unusual noise coming from that housing. Also there seems to be more slack on the right side when manually rotating the wheel vs the left side. I held the axle and the slack is not in the cv joints, it appears to be in the housing I described.

[gbeeley]

Originally Posted by Lesabrelover

Noise is definitely coming from passenger side. No noise when left side only turns.

Sounds like perhaps a bearing (if that tranny uses one for that piece), or the driveaxle rubbing against the metal part of the axle seal (not sure exactly how that piece is constructed). Anyhow, sounds very fixable without pulling the tranny out. It'd be good to have a mechanic look at it, or get a repair manual or subscribe to alldatadiy.com and get the diagrams there.

Worst comes to worst, if there has been a lot of play for a while, there is a chance you may want to replace a couple of gears/washers in the differential, for longevity. There are usually specs for gear lash for the diff. It may be good to change the fluid and filter, look for metal flake in the pan and filter, and if you find much, you might check that gear lash. AFAIK on that tranny the diff can be replaced without pulling/disassembling the tranny.

- GB

[BNaylor]

The part you are referring to is the final drive housing. The differential carrier assembly is located there along with the final drive sun gear, sun gear shaft, thrust washers, and thrust bearing assembly, etc.

[Lesabrelover]

Is this repairable/replacable without pulling the transmission?

[BNaylor]

Originally Posted by Lesabrelover

Is this repairable/replacable without pulling the transmission?

If you are referring to removing the final drive housing and differential it should be. Here is a procedure to do a differential replacement for a Grand Prix but the LeSabre should be similar and you'll probably have a little more clearance in the engine compartment. It will give you an idea of where to begin and the steps involved.

http://www.grandprix.net/upgrades/quaifeinstall.html

[gbeeley]

Originally Posted by Lesabrelover

Is this repairable/replacable without pulling the transmission?

I would think so, as long as there is enough physical clearance to get that cover off. You're lucky; the older GM trannies didn't have a diff cover - you had to pull the entire tranny apart to get the diff out....

You mention excessive play when rotating the passenger side wheel - when you rotate the wheel, watch for excessive up-and-down movement of the driveaxle where it enters the tranny. You might pull the driveaxle out and look at the axle and where it enters the tranny to see if you can visually spot where the problem is.

Some things that come to mind to check:

1. wear on any sleeve or bearing between the outside of the final drive cover and the diff carrier assembly, or where the drive axle goes through the carrier itself
2. wear on the drive axle shaft where it enters the tranny; if you recently replaced the drive axle, it is possible the replacement drive axle is out of balance which could have caused the unusual wear
3. wear on the drive axle seal in the tranny (which you'll want to replace anyhow)
4. gear lash in the diff
5. fluid and filter change is recommended And, if you find metal flake from the diff, perhaps a full fluid exchange might be advised.

Thankfully, since the noise only happens when the right axle turns, it is most likely not a problem with the final drive planetary gearset (or anything else further inside). You "shouldn't" have to mess with the planetary gears and needle bearings that were shown on the link bnaylor gave (but the illustrations/photos are good...), unless you buy an entire diff carrier assembly without those gears installed.

But you'll want to make sure you have all of the info on the clearances, part numbers, updates on diff washers, etc.

(edit) I would assume you've ruled out the wheel bearing itself?

- GB

[BNaylor]

Originally Posted by gbeeley

You "shouldn't" have to mess with the planetary gears and needle bearings that were shown on the link bnaylor gave (but the illustrations/photos are good...), unless you buy an entire diff carrier assembly without those gears installed.

But you'll want to make sure you have all of the info on the clearances, part numbers, updates on diff washers, etc.

(edit) I would assume you've ruled out the wheel bearing itself?

- GB

My recommendation before doing any type of tranny work is to have the right documentation. The best one out there and relatively inexpensive on places like EBay is the ATSG General Motors Techtran Manual. It covers final drive disassembly quite well to include all parts. There are numerous detailed illustrations.

[Lesabrelover]

Thanks for all of the help guys. I have my car fixed now. I was able to get the car up on a rack where I could diagnose the problem better and it turned out to be the inner cv joint that was noisy along with the hub bearing. After lightening my wallet $250 and a Saturday's work, I am back on the road again breathing a sigh of relief that it was not the tranny.