Hi everyone. I'd like some help with a differential that is causing a few problems please, or maybe they are challenges!

Firstly it gives out the occasional big clulk on moving off, forward or backwards. It is a non-posi unit, and when I checked this by turning the wheels, there is a little play at the pinion, but loads at the shafts.

In addition, there is a "tight" spot which you can get thru by hand with a hearty shove.

Looking up the numbers I appear to have a 11th April 1956 casing, numbered 3707806. This is on the driver side of the casing.
However, it has the strut bar brackets with struts attached (1959) and a drain plug (not 1959), which the Numbers bible says the latter shouldn't be there.

I'm aware the rear end needs overhauled/replacement, but it's what exactly is required.
I understand the axle shaft lengths are different between the years, so it's probably getting those measured that will decide what to order for the job if they are knackered.

Any contributions to this thread would be most welcome

Andy K

 

Hello Andy. The differential is the center section of the rear end housing and looks like the first photo below. You don't state what year your car is but know that the same differential was used from 1955 through 1962in corvettes, and 1955 through 1964 in full size cars. Over the years many corvettes had thier differentials replaced by newer differentials due to abuse or failure. The rear end housing followed the same route as people found that the newer axle housing with new bearing design and strut bars worked better for them. Removing the center differential is a simple task. 1) jack car up and support on jack stands 2) remove brake drums, driveline, and axel (s).
3) Drain the housing of oil by loosening the perimeter bolts. 4) Pry between differential and axle housing and the differential will fall out. The differential weighs about 80 lbs. so use a cushion under differential when removing or get help the weight. The differential can be rebuilt by an experienced person who has the specialty tools needed to set up the bearings. I see that you are in the UK so you should be able to find an experinced mechanic that can work on General motors, Ford, or any American car of the 1960's to 1980's era. The axle bearings can easily be replaced by a machine shop that has an axle press. Take note of the numbers on the old bearings when looking for replacement bearings. If money is no object I would send it over to Gary (GTR1999 on forum) and have him rebuild the differential but the shipping will get very expensive. Gary could also be a good source for parts if you need them. Good luck with your repair!
Just as a check you may want to check your U-joints and see if that is where your clunk noise is comming from.
Cheers!
RC

 

Hi RC

Thank you for the prompt reply. The car is a 1960 model, so there's a good chance the diff isn't going to be original judging by the descriptions.
i will need to be methodical with this, and work my way through the drivetrain. There is a lot of slop at the diff end when the wheels are rotated off the ground, even by classic car standards!
Finding someone proficient over here will be a challenge, but I am sure I will track them down.

Regards,

Andy

 

Andy Paul letchworth southern axles has just rebuilt my diff for me he used to be in Watford but is now in Lincoln but has friends in harpenden who deliver jobs to him not sure where you are based though
paul

 

Brilliant!. We're up in Scotland now, but know Lincoln very well. I'll catch up with Paul Letchworth and see what can be done,
Thank you!
Regards,
Andy