R380 differences

SMLE

Well-known member
Aug 21, 2014
94
0
GA
Anybody familiar with the differences between the R380 found behind a 3.5/3.9 rover engine and the R380 found behind the 4.0 in the disco 1 application?

Specifically interested in the input shaft dimensions...
 

robertf

Well-known member
Jan 22, 2006
3,948
8
-
I havent noticed a difference. The clutch is the same, I believe the input shaft seal and bearing are the same

Based on bits of internet research I think late td5 r380s had a diameter and bearing size increase but nothing sold in America
 

JohnnoK

Well-known member
Mar 19, 2017
101
1
Cape Town, South Africa
There are variations for different vehicles, with different bellhousings and input shaft lengths, and there are internal differences between the vehicle applications.
Having said that, a Disco box will be physically the same as another Disco box, but a P38 box won't fit a Disco or vice versa.

Scroll down this page to see some internal differences, for example.
 

SMLE

Well-known member
Aug 21, 2014
94
0
GA
Thanks guys. Have a '96 Disco 1 with manual transmission.

The diameter of the input shaft on my R380, where it fits into the pilot bushing (spigot bush) is approximately 0.751 inches.

Purchased a Chevy conversion kit. The pilot bushing I was supplied with has an internal measurement of approximately 0.593 inches.

Discussion with the supplier indicates their kit was for 3.5 and 3.9 engine vehicles. Mine was a 4.0 (looks like Rover switch to 4.0 in 1996 ?). Everything seems to be lining up correctly except for the pilot bushing issue...

The supplier is saying that the manual transmission on the 3.5 and 3.9 Disco 1's have a smaller input shaft diameter.

Purchased the kit over three years ago. Don't recall the web page for the kit indicating the 3.5/3.9 only thing, but I suppose I might have overlooked that...

I'm looking at having to try to remove 0.158 inches from the bushing, but am thinking I might bugger the oil impregnated bronze bushing by closing the surface pores. The other option is to machine the R380 input shaft down to the size of the supplied bushing, but am wondering if this would negatively impact the transmission.

Anyone with some experience or thoughts on this? Find an R380 from a '94 or '95 D1? Replace the input shaft with one from a '94/'95 ?
 

fishEH

Well-known member
Jan 26, 2009
6,403
23
Lake Villa, IL
Maybe let the supplier know that a 94-95 D1 had a 3.9 engine and uses the same pilot bushing as the later 4.0.
If I had to venture a guess, I'd say the kit was designed with Defenders in mind and there may be differences in the pilot bushings with the older engines in them. But that is purely a guess.

Thanks guys. Have a '96 Disco 1 with manual transmission.

The diameter of the input shaft on my R380, where it fits into the pilot bushing (spigot bush) is approximately 0.751 inches.

Purchased a Chevy conversion kit. The pilot bushing I was supplied with has an internal measurement of approximately 0.593 inches.

Discussion with the supplier indicates their kit was for 3.5 and 3.9 engine vehicles. Mine was a 4.0 (looks like Rover switch to 4.0 in 1996 ?). Everything seems to be lining up correctly except for the pilot bushing issue...

The supplier is saying that the manual transmission on the 3.5 and 3.9 Disco 1's have a smaller input shaft diameter.

Purchased the kit over three years ago. Don't recall the web page for the kit indicating the 3.5/3.9 only thing, but I suppose I might have overlooked that...

I'm looking at having to try to remove 0.158 inches from the bushing, but am thinking I might bugger the oil impregnated bronze bushing by closing the surface pores. The other option is to machine the R380 input shaft down to the size of the supplied bushing, but am wondering if this would negatively impact the transmission.

Anyone with some experience or thoughts on this? Find an R380 from a '94 or '95 D1? Replace the input shaft with one from a '94/'95 ?
 

SMLE

Well-known member
Aug 21, 2014
94
0
GA
Thanks for everyone's input.

The supplier has basically told me I'm on my own.

I'm starting to look around at custom milling shops, my own metal lathe or finding a long shot off the shelf solution...
 

robertf

Well-known member
Jan 22, 2006
3,948
8
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I think they do custom work if you can't find a local shop to do it


what engine are you putting in?
 

discostew

Well-known member
Sep 14, 2010
4,624
18
Northern Illinois
Thanks for everyone's input.

The supplier has basically told me I'm on my own.

I'm starting to look around at custom milling shops, my own metal lathe or finding a long shot off the shelf solution...
Are we talking about a brass pilot bushing for the rear of a chevy small block? A vise and a drill bit should be fine.
 

SMLE

Well-known member
Aug 21, 2014
94
0
GA
Chevy 350.

Are we talking about a brass pilot bushing for the rear of a chevy small block? A vise and a drill bit should be fine.

It's an Oilite Bronze bushing. I probably will go that route to begin with and see how long it lasts while I find a more permanent solution.
 

4Runner

Well-known member
May 24, 2007
334
0
Boise Idaho
You could always machine it to fit and send it to a company to be coated with something. Probably wouldn’t cost too much.