1971 Rear End.. What is it?

[Raggedy Ann Riviera]

Hello! 
My 1971 Riviera has been making rear end noise since purchased in 2020. Had it checked out and the shop said the pinion bearing was worn and making the noise but nothing so bad that it needed to be fixed immediately. Recently the noise has gotten louder so think it’s time to do something about it. FYI I only drive the car a few miles from where it’s stored about once a month so it’s not getting flogged in any way. Also no obvious gear oil puddle or drip under it either. Anyhow I know nothing about the rear ends these cars are equipped with and knowledge is power when dealing with a greedy shop. (especially if one is female) I was initially going to have it rebuilt somewhere ($1,500 expense) but my husband thinks it might be more cost effective to just buy another rear end and have it installed. Again I don’t know if the rear ends in these cars are oddballs or relatively plentiful. I do know my current setup DOES NOT have posi as I accidentally executed a one wheel squeal merging onto a busy highway, lol! My riviera is relatively low optioned, mostly cosmetic stuff such as the vinyl top and bucket console interior.. deluxe style at that.. if that’s of any help? ALSO of note I’m going to have the wheel bearings checked to rule that out as well.. Thank you in advance! 

[gungeey]

 

Didn't they have the Max Trac option in 71?

That would be an oddball.

 

I think if the shop was greedy they would of not sent you off but said it needs to be done immediately. Likely, they don't want it in.

 

You need to find a competent shop you can trust.

 

My opinion: If 15 bills guarantees my problem goes away, I would write the check. Or else learn to do it myself.

 

Good luck in your endeavor

[Raggedy Ann Riviera]

31 minutes ago, gungeey said:

 

Didn't they have the Max Trac option in 71?

That would be an oddball.

 

I think if the shop was greedy they would of not sent you off but said it needs to be done immediately. Likely, they don't want it in.

 

You need to find a competent shop you can trust.

 

My opinion: If 15 bills guarantees my problem goes away, I would write the check. Or else learn to do it myself.

 

Good luck in your endeavor

To answer a question with a question how would I be able to tell my car has max trac? Was there a switch or button for that on the dash? If so my car does not have it.

 

    You are correct, the shop that initially looked at it did not want to rip me off, but they don’t rebuild rear ends. To clarify they’re just a general service mom n pop, just wanted them to look at it to see how soon I do need to take it to a rebuild shop.

 

    The one that was trustworthy in town no longer works on Classic cars. One of the employees did want to take it on irregardless (how I got a price) but seemed a bit too overconfident.. and ended up doing a less than competent job on my husband’s late model GMC. 

 

     But still, what rear end (s) do they put  in a ‘71 Riviera other than the max trac? 

[NTX5467]

If it has "Max Trac", there will be a switch on the lower edge of the upper instrument panel ledge.  It has nothing to do with the rear axle, just sequentially kills the spark to cylinders to limit power to allegedly help with wheel spin reduction.

 

Back then, Buick designed and built their own unique rear axles.  There might be other non-Buick applications, but I suspect not.

 

If you don't already have one, you need a Buick-specific factory service manual.  It should detail the rear axle and how to identify it.  I have downloaded files of the Buick parts books, pre-1973, which also have mentioned of rear axle ID and ratios.

 

If the differential internal gears have worn, might be cost effective to swap in a limited-slip differential rather than rebuilding what you have.  Provided somebody sells the needed unit.  When you take the differential carrier out, you can also plan on putting new side bearings to replace the existing side bearings.  Pinion bearings, too.  Reusing the existing ring gear and pinion gears.

 

You'll also need to inspect the axle shaft bearings and seals, too.  I believe the bearings probably need to be repacked with grease, too?

 

If you get a replacement axle assy from a salvage yard, you could very well end up just where you presently are, as to wear issues!

 

Finding a competent rear axle shop to do the work can be a task, but a good investment in finding them can be good, too.

 

Some shops who do not want the job can price their estimate high enough to potentially send you elsewhere.  Having a car tie-up a stall for a longer-than-normal period of time, waiting on parts, is not what they usually want to see or desire.  So check on parts availability of the allegedly-needed gears, their prices, first.  If the car's still drivable, but getting noisier, it still can be driven a bit.  Might get a second opinion estimate from another shop or so, for general principles.

 

Considering that Chevy and GMC are still building rear wheel drive pickup trucks, they could well have a tech or more that knows how to do good, OEM-level rear axle work.  Then, with a willing co-conspirator in the parts department, you might shop that angle, too.  And most dealerships have a "shop warranty" period stated on the bottom of their repair orders, too.  Might be higher than a private garage in labor rates, but it could be a better alternative.

 

Just some thoughts,

NTX5467

[Raggedy Ann Riviera]

NTX5467 (sounds like an aircraft tail number  )

 

Thank you so much for such a helpful detailed response!
 

It certainly does not have max trac!
 

Although my husband and I like to wrench on our own cars we just don’t have the best space, or know how to do a rear end job. I did grow up around car mechanics (unfortunately, lol, Ford guys) and do get a gist of what you’re talking about. I did have the same concern about doing a straight up

swap, as the car is much older and less plentiful than the one my husband  did (‘86 Olds Cutlass) new parts would  be much better.

     I still gotta make sure that 455 stays healthy so I’ll at least drive it around the neighborhood once in awhile despite the noise.
   I do have a factory buick service manual! , didn’t think of looking there, lol! Knowing what I have will be a big key to the puzzle to see if a shop will be willing to/ can work on it or not.. instead of being like “It’s an old Buick, I don’t know, derp.”
    I have a network of “classic car buddies” to consult but we pretty much knew of this one shop as a go to, which obviously no longer takes such work. Myself being a business owner totally understands your explanation of why. 
    Although rough this car is my baby so will be pretty thorough in finding a shop. 
   Again thank you so much! 😁

[EmTee]

Asking around through your 'car buddy' network is probably your best bet.  You may be able to identify someone who works at a dealership or other repair shop who takes 'side jobs' at home.  Has anyone checked the oil level?  It's odd that the pinion bearing is shot and yet the seal isn't leaking.  Just make sure there's still oil in it before you drive it.

[Raggedy Ann Riviera]

3 hours ago, EmTee said:

Asking around through your 'car buddy' network is probably your best bet.  You may be able to identify someone who works at a dealership or other repair shop who takes 'side jobs' at home.  Has anyone checked the oil level?  It's odd that the pinion bearing is shot and yet the seal isn't leaking.  Just make sure there's still oil in it before you drive it.

Emtee,

    Hit the quote button, no need, oops. 😛

   For sure I’ll ask my friends, especially since it’s been a couple years since I had it checked/was considering it. They may have found a new go to rear end place. Unfortunately there where not many to begin with. The one that no longer services Classic cars was relatively centrally located .. the others I know of are going to be an hour drive away 😬

      I’ll get under the car and take a look at that seal too. When I had it checked they said the oil level was was fine, but that was a couple years ago. I’m temporarily storing it in my mom’s garage, if it was leaking a lot I certainly would have heard about it, lol! It was a barn find so leaky seals have been a thing. Had the transmission rebuilt because of that too. 
   I’m sure I’ll find a reputable person, if I don’t find a reputable shop. Of course the reference will have to be really good. I had some shade tree people in my hometown and yikes! 😵

    Thank you for the advice, totally appreciate it! 😊

[60FlatTop]

1 hour ago, Raggedy Ann Riviera said:

When I had it checked they said the oil level was was fine, but that was a couple years ago.

That is a 50 year old car and you can compare the mileage over that time to the amount of time it may have set idle in an unconditioned space. There could be up to a quart of condensed water to churn around with the oil every time it is driven. Rear end and transmission lubricant are almost universally overlooked when recommissioning a long term stored car.

 

The '71 Riviera has an easy to remove cover on the rear end. Probably not a bad idea to dump it now and refill to remove what may be contaminated. At least you can get a peek inside.

 

All these aged cars need attention to their condensation traps. I like to give a drain, 30 miles drive, drain, 30 mile drive, then a drain and refill on a car with an unknown lubrication and storage history.

 

On the cost, there are six 50 year old bearings counting the pinion, third member, and axles. Averaging $50 is probably a little low but there is $300. Spending an 8 hour day at $100 per hour gets it up to $1100 and that is on the low end. There can be a little extra for "training" if they are stretching their limited experience on the job. Then you allow for one call back on the job. The rearend could be fine but the customer might whine. And you pretty much have it.

 

Getting an old car fixed today is a lot like getting a foreign car fixed in the 1960s.

 

The take away: flush those lubricants on the new acquisition. The level could be supported by water.