Joining SD1 LT77 to auto 3.9 RV8

ratwing · Post by **ratwing** » Sat Aug 30, 2014 8:18 am

I'm still exploring options to replace a worn out '72 p6 V8 & 4 speed gearbox and am wondering if the complete flywheel/clutch/bellhousing/LT77 from an SD1 that I've been offered will fit a 3.9 auto engine from a Range Rover?

Its got a serpentine belt, efi and distributor if that helps but I'll using my carbs instead of the efi.
I know I'll have to alter the propshaft/gearlever/gearbox mounts/speedo drive/clutch release/carb needles etc but that won't be problem.
(Ideally I'd like a complete engine/gearbox unit like this one but its gone beyond my reach now)
http://www.ebay.co.uk/itm/121416504001? ... EBIDX%3AIT

ChrisJC · Post by **ChrisJC** » Sat Aug 30, 2014 3:49 pm

The back of the block is the same across all rover V8's. As is the crankshaft.

The only thing to be aware of is that manual cars have a bronze (I think) spigot bush, whereas auto's either don't have it or have a steel one (I think they don't have one actually).

So you have to get that right, and everything else will bolt straight up.

Chris.

Denis247 · Post by **Denis247** » Sat Aug 30, 2014 5:02 pm

If I recall, and it was a looong time ago, I had to replace the bush when going from an auto to a manual. It was still a bronze bush, but with a bigger hole. I can remember filling the hole with grease then pushing a drift into the hole, with the grease forcing the old bush out.
The new bush should be frozen before fitting, slips right in.

As I said, this was a lomg time ago when I first started playing with fitting one of these engines.

mike-b · Post by **mike-b** » Sat Aug 30, 2014 9:30 pm

Hi,
Chris is correct when he states an auto box does not use a spigot bush, my BW35 auto never had one on my 3.9. There is no need as a plate is used instead of the flywheel and the torque converter bolts to the plate. the plate has a ring gear for the starter and is bolted to the engine the same way as a flywheel.
They are used on the manual `boxes, the size is dependant on the manual gearbox you intend to fit, i.e. a T5 has a different inside diameter to a LT77 so be sure to get the correct one. The outside diameter is of course the same
If you are having to alter your propshaft ( most likely ) get it balanced as well.
Hope that helps, Mike.

ratwing · Post by **ratwing** » Mon Sep 01, 2014 7:14 am

Thanks guys, thats one less thing to worry about

harvey · Post by **harvey** » Mon Sep 01, 2014 2:12 pm

mike-b wrote:Hi,
Chris is correct when he states an auto box does not use a spigot bush, my BW35 auto never had one on my 3.9.

The BW35 & 65 both have a spigot bush. (Or should have).

DaveEFI · Post by **DaveEFI** » Mon Sep 01, 2014 4:17 pm

According to the Rimmer site, there are two different bushes for the SD1 - manual and auto. And a third one for both manual and auto on a 4X4.

Denis247 · Post by **Denis247** » Mon Sep 01, 2014 5:47 pm

Denis247 wrote:If I recall, and it was a looong time ago, I had to replace the bush when going from an auto to a manual. It was still a bronze bush, but with a bigger hole. I can remember filling the hole with grease then pushing a drift into the hole, with the grease forcing the old bush out.
The new bush should be frozen before fitting, slips right in.

As I said, this was a lomg time ago when I first started playing with fitting one of these engines.

I still have the phosphor-bronze bush I took out of an auto engine when I changed it for one with a smaller bore to fit an LT77. The auto engine defo had a bush.

DEVONMAN · Post by **DEVONMAN** » Mon Sep 01, 2014 7:02 pm

If you are dumping an auto box in favour of a LT77 then remove everything to do with the torque converter mounting and fit a spigot bush in the hole in the end of the crank to suit the LT77 shaft (ie an SD1 type bush.)

The way the torque converter was mounted has changed over the years and some had a thin bronze bush and others just located straight into the hole in the crank.