Rebuilding TVR Vixen 2500 Rear Uprights...

[Rocky_LC]

I've got a spare set of Vixen 2500 uprights. I figured that since they were off the car, I could rebuild them at a leisurely pace.

There are some resources on the internet that discuss the procedures and some of the pitfalls, which have been pretty helpful.

I do have access to a very capable machine shop, with a powerful press, which is a great benefit in the disassembly, and making up some of the tooling that I found I needed for the job.

Once I started taking them apart, I found someone had already been inside, and I found out why.

Anyway - they were pretty typical looking for 50 year old parts, but I expected that. I pulled off the brake backing plates, and the inner drive flanges of both. One of them was already loose, and the inner and outer bearings (including the outer race) came right off the shaft. Anyway - lots of greasy cleanup was done to make follow-on tasks more pleasant.

The brake mount plate was removed, and those were cleaned up and painted.

The squash tubes were removed and cleaned up, and all parts were marked to keep them straight for future reassembly.

 

[Rocky_LC]

Cleaned up and painted the inner drive flanges.

The seal surface was a bit chewed up, so I ordered two "Speedi Sleeves".

In case anyone else is doing this, the Part Numbers are:

SKF 99155 (For Shafts sized between 1.552" -> 1.553").

The SKF Box says 1.548” - 1.555”.


NOTE: Some of the pictures highlight the "flaws" more than you would expect. These will look just fine when they are all assembled!

 

[Rocky_LC]

Once I got the quillshafts out, I had to press out both the inner and outer races.

I turned down a nice 2" thick piece of 7075 Aluminum to a diameter of 1.965", and then cut it in half with the bandsaw. I had to trim off some of the tips of the semicircles so I could drop it down past the races, and reassemble it in the inner bore of the uprights. It looked really sweet after I got done turning it, but not so great after I got done on the bandsaw.

Anyway - to press out the bearings, access is initially restricted by the smallest diameter of the races (1.820").

Anyway - my tool slips right in and gives me a great surface to push on with the press. The races came out with no trouble.

Lots of big flat surfaces to rest the upright on, to push the races out.

 

[Rocky_LC]

Before I had done all that, I had gotten the quill shafts, and the uprights as clean as I could, just to make the job easier.

There's still work to do, but....

(And yes, I know the race spun on the lower quill shaft in the picture below)

I've got all the bearings and seals but need to find a source for the bushings at the top of the uprights, and check into sourcing new quill shafts.

I also have to get the race off the quill shaft in the lower picture. I might try the "heat a spot to red hot with a torch" trick....

 

[Rocky_LC]

Here's the tooling to push out the bushings on the top of the uprights...

 

[Rocky_LC]

Pushing the quill shafts out of the hubs on a press.

The press is loaded to 10 tons, then a number of sharp impacts on the pusher plate facilitate the separation of the quill from the hub.

 

[Rocky_LC]

Since I have access to a very good machine shop capability, I have decided that I’m going to make the replacement quillshafts myself.

I have two 12” bars of S300 steel on order from McMaster-Carr. It’s fairly expensive stuff just by itself.

Here’s a description of the steel:

S300M is a high performance alloy steel which is a vacuum melted grade, supplied in the normalised and tempered/softened condition to enhance machinability prior to final heat treatment.

It has a combination of ultra high strength, good fatigue resistance and excellent transverse properties, and as such finds many applications in the aerospace industry, such as undercarriage components, gears and shafts.

The plan is to duplicate the stock quill shafts, and then heat treat them afterwards to harden them.

Heat treat specifics will follow.

Currently I’m taking measurements, and working up my drawing, and machining operations plan…

Rocky