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94 FWB rear end question

4254 Views 12 Replies 4 Participants Last post by  BigBlack94
I have noticed a noise from the rear end of my 1994 Fleetwood. Once I get up to about 35 mph I can hear a deep whirring sound that continues as I drive up until I slow down.
I went to a mechanic who says that I have a bad bearing and that my options are to rebuild the rear end at around 900 dollars or to replace the rear end with another from the junk yard.

If I take the junk yard option, what are some things that I may need to be aware of ?
Are there some other rear ends from GM vehicles that I could look for that will be a good replacement ?


To the moderator, could you please remove this post as I wanted to add some more information and made a double post. Thanks
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You may be able to use axle saver bearings. Some of these axles use the axle itself as the race for the wheel bearing. After a while the axle gets a notch due to wear.

If there is play in the axle bearings due to axle notching the axle saver bearings will offset the area where the bearing contacts the axle surface.

I've used these many times on older Cadillac rear axles with good results. Yours is similar IIRC. Plenty of people here would know.

First you need to verify the problem is the axle bearing. Similar sounds can come from worn ring and pinion and/or some hack mechanic replacing pinion seal without knowing what they were doing.

My 1980 Cadillac has 70k original miles and is just starting to make a little noise from the wheel bearings.
The problem with the GM 8.5 is it uses the axle shaft as the bearing race. Once that bearing starts to go, it will groove the shaft. While axle saver bearings are available, most have reported that they don't last long. To make the situation more complicated, your rear doesn't interchange with anything else (other than other Fleetwoods). The D body Fleetwood used a unique four channel ABS system, where the B bodies (Caprice, etc) used a three channel ABS. The axles, housings, and even center section are different.

The axles are available. Bottom line? Time to crack open the rear end and start looking for problems. Rebuild, don't replace.

HOWEVER, make sure that it's not the U joints first! They are so cheap and easy to do, I would highly recommend doing them first.

Unfortunately, in my experience, bearings don't sound like the symptoms you are describing. Bad gears sound like that. Have you noticed a leak from the pinion or the cover? Doesn't really matter, though, if you have to replace gears, you should do outer bearings and seals, too. It will be easy to tell if it is the outer bearing, just pop off a brake drum, and wiggle the axle up and down. Anything more than a tiny bit of movement means bearing. Wet inside the the backing plate means bad seal (or leaking brake cylinder).

I think that's it, OTOH.
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Feh. Probably only 80k on the bearing savers in my 2.28 posi currently on vacation in the garage.

Only got about that on another car I fitted with those before it was junked.

This was 20+ years ago. Maybe they don't make them so well anymore.
I have a NEW set of GM axles for my 94 Fleetwood that I never put in. My right side was lunched from the wrong diff gasket issue. Left side was fine.

I was keeping them for a rainy day but my Fleetwood isn't going to get fixed anymore....
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I have found a 95 Fleetwood in a pick n pull yard, I was going to get ahold of. Since it seems that I cannot interchange the axle with anything other than another Fleetwood, I should be able to get this and bolt it right up ?
I was going to put new wheel cylinders and brakes on it before I install it, and I guess that I should drop the pumpkin cover and take a look inside before I drop it.
When I was looking into getting it rebuilt or worked on I was always asked if it was a 10 bolt or 14 bolt rear end. Can anyone tell me the difference between the two ?
Limos were 9.5 semi floater 14 bolt axles. Bolts in from what I gather. But very heavy axle. And they come with the half ton truck 2.5" drums.

All others have 10 bolt axles.

I put a 14bolt sf in my 96 Suburban probably 50-100 lbs heavier than 8.5". I could easily move the 10 bolt around. The 14 was way heavier.
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If it is the exact same model, it will have the same gears. There were three different gear ratios for your year. Check your SPID sticker in your trunk for your G code to find your ratio, and do the same for the junk one. You can use a different ratio, but your speedo will be slightly off. Can be corrected with programing. Or, swap your gears into junk rear.

Re: axle saver longevity. I was strictly speaking of the 8.5. That rear just tends to eat them up. Likely related to the rear gasket issue. Yes, axle savers are well proven on other rears, and I would recommend for those applications.
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I am still puzzled how American Axle, after making millions of axles for GM, screwed up the gasket on these, AND how long it took for it to be discovered.

AND the fact that GM only honored repairs on the 9C1 and 9C6 cars (and likely limo sedans such as the R1P car, Rest 1n Peace?), but everyday joe's got the short end of the stick on it.

GM Customer service shines through!
Re: axle saver longevity. I was strictly speaking of the 8.5. That rear just tends to eat them up. Likely related to the rear gasket issue. Yes, axle savers are well proven on other rears, and I would recommend for those applications.
If one replaces the gasket with one with all the necessary holes why would a new bearing saver wear out before its time?
I don't know, but others have reported that exactly being the case. A good friend, local to me, went through that in a roadmaster.
My right axle was toasted, but my left was fine. Guessing all the hard right hand corners.... :)
My right axle was toasted, but my left was fine. Guessing all the hard right hand corners.... :)
You know, now that you mentioned this about the right axle, something else comes to mind. I have put lowrider style (13 X 7") rims on a Fleetwood before and for some reason, the right rear wheel always rubs on the inner fender. Which requires some slight modification to the inner fender and skirt to make it not rub when turning or lowered.
I have heard of huys getting the axles "shortened" to alleviate this issue, but I was wondering now if there is a difference in length of the left and right axles of the Fleetwood.
does anyone have any idea as to what else can be done to make a correction to the rught side axle to keep that from happening ?
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