TR4/4A Alternate differential for TR4A

[boeingpilot]

I met a fellow a few years ago who had (I think) a Nissan differential in his TR6. Anyone here have the same setup? If so, what are the details? Would it work on a TR4A? WHat mods would have to be done?

 

[aeronca65t]

I've heard the same thing, but have no personal experience. What I do recall is that the diff was from a Datsun (Nissan) 510 and that the rear diff in modern Subarus is the same unit. If this is true, it would seem to be an easy way to get a limited slip diff. You might want to go to a junkyard with a tape measure and look under some recent Subarus.

 

[martx-5]

Goodparts has a Nissan R200 upgrade kit for the TR6. It should fit the TR4A w/IRS, as Ratco's frames for the TR6 and TR4A's are the same except for the steering rack mounts. But call Goodparts to verify.

 

[tr8todd]

You might also want to look at a BMW diff. They basically come in two sizes. Big and small. The smaller ones are plentiful, cheap, come in different ratios, and many have limited slips. The basic design has a complete subframe that can be mounted into just about any car. The subframe is shaped like a K with the straight part of the K at the front. V shaped control arms mount at either side. Springs and tube shocks mount on the control arms above the bearing carrier. The subframe mounts in 2 spots at the very front and the pumpkin has a mount on it's top. Even the brakes and sway bar mount to the subframe and control arms. It's a somewhat common practice for the BMW guys to adapt complete setups from newer cars into the older models. I recently saw an old Beetle with a front engine and a BMW rear end out of an early 90's 318is. Turns out the VW axles bolted up to the BMW rear. Makes sense since it's all coming out of the same German parts bins. The pumpkins and shafts come in various widths and lengths based on the application. Mix and match or add spacers to get the wheel base you want. Only problem will be the wheel bolt pattern. Doubt they are the same as your TR. Some day I'll get around to stuffing one under a TR8. Narrowing and adapting Ford 8.8's, which is the common practice for the TR8, is alot of work just to get a posi and rear discs. In the end the 8.8 is still just a heavy stick rear end, granted it can handle some serious power, but an independent rear would be sweet.

 

[BobbyD]

I did the Nissan diff upgrade in my TR6 last year and it's so nice to have a quiet leak free smooth turning diff. The whole installation is documented on my site.

But you should email Richard Good and ask him about compatibility with the TR4A.