This morning I took my '64 Valiant into a reputable, local garage to have the rear wheel bearings replaced and they hit a problem. The bearings they ordered are too large (dia) for the axles. They checked all the local parts places and their books showed the same bearing.

A call to the local oldtimer in the parts department at the Dodge dealer also proved fruitless since Chrysler no longer carries the parts. He couldn't understand why there was a problem since the only model he could recall being different was 1967.

The mechanic measured the old bearings and is trying to find something through a bearing house, but it might take a couple of days.

Does anyone have info that might explain this?

Murphy's Law #14:
When you need something very badly, no one has it.

Jerry

_________________
There's a difference between ignorance and stupidity.
Ignorance is not knowing any better.
Stupidity is knowing, yet doing it anyway.

The bearing sizes changed over the years. I ran into this problem when replacing a axle bearing in my old '64. In my case, somebody had replaced the OEM axle with a later model.

A-Body 7 1/4 rearends use 3 different axle bearing sizes over the years.
All of the 7 1/4 axle bearings are sealed ball bearing type.

- 60 to 62 (and some "spill-over" into 63) used the smallest bearing this one is a real problem. These wear-out fast and are no longer available new. These early bearings are hard to locate in general.

- 63 to 72 / 76 (small lug pattern axles) has a larger bearing that is still available. This is the most common 7 1/4 axle bearing.

- 73 to 76 "big lug" used the largest axle bearing.

All the axle housings and backing plates are made to fit a certain size bearing so if you want to up-grade, you need to swap housings and the brake backing plates.

Take a measurement of the bearing OD and we can figure-out what type it is.
DD

This was asked over at .com, and I 'helped' Matt 'reword his inquiry. Since this post touched on the subject to a certain extent that the bearings might have to be changed for his app...but still not sure about axle shafts....

Any one be able to 'shed light' on what his 'best' option is?

=====>

Matt has a 1965 Valiant and wants to swap to disc brakes and an LBP 7 1/4" rear with 10" ... shipping to the nice island chain of Hawaii isn't cheap (between them and Japan, Alaska, and Australia you'd have to be rich).

He doesn't have access to an LBP axle assembly on his island, and we know a 1973-1976 LBP axle assembly will bolt up under it.

Hollander's says you can swap the axle shafts on all the A-body 7 1/4" rear axles, but the 1973-1976 assembly is 1.8" narrower flange to flange than the 1963-1972 assembly. I also hav been told that the 10" drum brake backing plates from a 1973+ unit might not bolt up to the 1965 unit, due to axle tube flaring and size....

So could someone who is in the know, line us out on who's right, and why/why not of swapping 7 1/4 axle shafts and brake assemblies.


Thanks for you help, we'll get him straightened out, and get the proper parts to him.

-D.Idiot

I don't know if this will help, but I can say for sure that I was unable to swap axleshafts between my '70 valiant and my '76 dart, both with 7 1/4's. I seem to recall that the axleshafts in one wouldn't engage the splines in the other. In any case, it was a no-go. If hollander's says all 7 1/4 axleshafts are interchangeable, they're definitely wrong.

_________________
Everyone driving slower than me is a moron. Everyone driving faster than me is an idiot. With all these morons and idiots on the road, I can't get anywhere!

I had heard the 1973-1976 tubes were flared and they were narrower assemblies, needing shorter axle shafts than the 1963-1972 units....

It's weird seeing some guys say 'yeah they fit', and some articles say 'no they won't '....

Thanks for the input,

-D.Idiot

That would certainly explain what happened when I tried to swap axleshafts.

_________________
Everyone driving slower than me is a moron. Everyone driving faster than me is an idiot. With all these morons and idiots on the road, I can't get anywhere!

There is a lot of confusion over the 73-76 A-Body lug patterns just because Chrysler used both the 5 on 4 inch (SBP) and the 5 on 4 1/2 (LBP) during this period. The Disc Brake option was what decided which lug pattern got on the car.

As stated before, the axle bearing size is larger for the LBP 7 1/4, you can not just swap axles into a SBP housing to get the bigger bolt pattern.

Once I swapped an E-Body LBP 7 1/4 for an 8 3/4 and found that the brake backing plates / bearing retainers from the LBP 7 1/4 had the same 5 hole pattern as the 8 3/4, the OD of the axle bearings also looked the same. I was able to use the 7 1/4 brake assemblies on the 8 3/4.

Based on that observation, I do not see an easy way to get the LBP axles to swap into the SBP housing. One "longshot" is to see if the axle bearing IDs are the same size, that would allow you to swap the 64-72 SBP axle bearing onto the 73-76 LBP axle shaft, you would also have to use the "4 hole" SBP bearing retainer and backing plates. This would get the LBP axles into the SBP housing.

Now you have the issue of different axle flange off-sets between the SBP vs LBP brake assemblies. I do not know if a mix of brake parts would work-out, you basically need the LBP drums and the SBP backing plates
but who know what brake shoes would clear everything.

Sorry I do not have more or better info.
The 7 1/4 is so weak that I don't spend much time with them, other then swapping them out for a 8 3/4.
DD

So just what is the bearing OD and ID for the early sbp 7 1/4"?
-Jesse