rebuilding 1916 differential

[Jon]

Seller advised that I immediately rebuild the differential on my newly acquired 1916 Model T. The mileage is unknown but thought to be low (although the spindle and tie rod bushings are shot). Said the babbit spacers disintegrate and destroy gearing. How likely is this to happen? Should I be urgently concerned, or do it "down the road" ?

[Charlie B in N.J.]

Apparently the only real way to know is pulling it apart. You can jack up the rear and check on the in/out play of the wheel and perhaps getting a look at the rear end fluid but re-read line one.

[John kuehn]

If the spindle and tie rod bushings are in bad shape probably any other chassis parts are too.
That means the differential would likely be also. After 100 years things do eventually wear out.
As far as the front end is concerned it would be best to remove the front end assembly and replace all the bushings in it. You may be surprised how much they are worn if you jack up the front end and move the steering wheel slowly back and forth.

[Steve Jelf]

Be urgently concerned. If the seller said do it, assume it hasn't been done. If it's never been done, those thrust washers are 104-year-old Babbitt. If they haven't disintegrated yet, they will. In some driving situations, that could kill you. Better to take care of it before trouble strikes than after.

http://dauntlessgeezer.com/DG79.html

[John bevardos]

My 24 roadster diff blew apart after the babbit thrust washers broke--no brakes is pretty scary . I rebuilt with brass thrust washers and added a/c brakes. john

[Norman Kling]

Unless you know for sure, the babbitt thrust washers have been replaced by bronze, for safety sake be sure to open it up and look. Unlike modern cars which can still stop with a bad differential, the T loses all braking except for the parking brake when the differential goes out. You can't even use reverse or low to slow it down. Even if you replace the washers, other things could cause problems such as the drive shaft, universal joint or axles. I would recommend not only rebuilding the rear axle, but adding auxiliary brakes for safety.
Norm

[John kuehn]

I agree with the seller. If anybody would know he would know how the car runs, drives and what noises it makes. At least he told you about it and that’s a good thing!

[Rich Eagle]

All the above is good advice. Tearing the axle down is a good idea and a rewarding experience. While you are in there you may want to replace the ring and pinion and other parts. I have torn half a dozen working axles down after reading these notes of caution and impending disaster and never regretted it. The last two were torn down because of stories about modern fluids attacking the bronze thrust washers. Each time I found the axles good enough to have run a few hundred miles further.
As I am sometimes a fly in the ointment and don't what anyone to have a catastrophic accident and I will encourage you to attend to this soon. However I will show you a stack of babbitt washers that survived thousands of miles without disintegration.

That differential could go many more miles if there is not excessive end play in the axles or if the lubricating oil shows no sign of babbitt in it. How and where you drive the car could influence how urgent the rebuild is.
Erroring on the side of caution is a good thing but I find I am less likely to drive my cars when I hear disaster stories. I do know they are well meaning and dangers are out there.
Rich

[Allan]

If the car has been restored at some stage, I would rebuild the back axle so you know what you have.

If it is like my barn fresh buckboard, I would drive it and see how it performs. I have not rebuilt Henrietta's back axle as I do not wish to disturb functioning, original, undisturbed parts. I have checked end play, axle wear and lubricant levels, and have installed new, lined emergency brake shoes to have the best handbrake I have ever had on a T.

Allan from down under.

[Kerry]

This is the very reason I tag the out side of the housing after a re-build, so the next owner knows what he's got.

[Allan]

Sorry Frank. When I rebuilt the back axle for Dr Verschoor, I didn't think to do that.

Allan from down under.

[Altair]

I dodged a very serious accident when my differential let go, I had it wound up peaking about 30 mph and a lady pulled right in front of me I only had time to hit the brake hard and the pinion stripped, there was no teeth left on it and no babbitt washers left in the housing.