The V8 Owners Forum -

Hi all, was wondering if anyone could suggest a suitable auto gearbox that would work with a 4.6 Rover engine. One that is readily available and fits without too much fiddling... I have a SD1 3.5 with an auto, but some friends are suggesting the box wont fit/not suitable..?

And is it right, that the engine crankcases are different between a 3.5 and 4.6..?

Thankyou...Bazza

The crankcases between 3.5 & 4.6 are the same, but the sumps are different.
The sump type is determined by the timing cover fitted - i.e. a serpentine timing cover needs a different sump to an SD1 timing cover.

In my opinion, the ZF4HP22 autobox is a good box to fit to a Rover V8. It was fitted to countless Range Rovers in 4WD form, and BMW, Merc, Volvo, Jag in 2WD form. Mixing and matching will give you a 2WD box that fits the Rover V8. The holy grail is a Sherpa Van V8 Auto gearbox as that is basically a 2WD Range Rover autobox. Pretty rare though!

Chris.

Hiya Chris, thanks for the reply.. I was told theres a difference that can be identified by some bolts somehow or other..? Between an early/late type..? I am only just begining to learn about Rover V8s.. I dont think I have a P6.. Its in a trike. If I posted some pictures could you maybe help me ID it..? Ive been having overheating problems and I did a compression test on it which gave all round poor readings (between 95 and 110 psi) I might as well replace the motor, rather than buggering around rebuilding and was thinking of going for a 4.6 while I was at it.. So the 4.6 is the same externally..?

Cheers...Bazza.

you are probably on about the crossbolts on the 4.6 block. They go through the block in a row above the sump and bolt through to the crank main caps. This has absolutely nothing to do with a box bolting on.

katanaman wrote:you are probably on about the crossbolts on the 4.6 block. They go through the block in a row above the sump and bolt through to the crank main caps. This has absolutely nothing to do with a box bolting on.

Hi....so if l swapped my 3.5 for a 4.6 it would bolt straight in and l could try and see if my gearbox was up to it by simply bolting that on too...? And my exhaust and carb/manifold setup would be no problem to use also, lm guessing..?

Thanks............Bazza

it will all bolt in but remember a 4.6 is a fuel injected engine as well as digital ignition. You will either have to sort that lot out or use a carb and a dizzi the dizzi requiring a different front cover and all that. Its not as simple as bolting it in but all the details can be found on the forum so have a search and be sure what your up against before you commit to buying an engine.

This web page shows the build of a 4.6 litre Rover V8 with carburettors and a distributor. It's basically done with a 4.6 block, but 3.5 sump, front cover, inlet manifold. The crankshaft spacer is shown.

http://www.cowdery.org.uk/v8rebuild.php

Also this page:
http://www.cowdery.org.uk/miscv8.php
has a picture of the early and late type sumps side by side (I haven't got the even later aluminium cast sump yet....)

Chris.

Cheers guys That cowdery web site is fantastic...incredible run of detailed photos...

So...Have l got this right...? l can use a 4.6 if l use my 3.5 sump and front covers/distributer...and l can also use my carb/manifold setup and exhausts...AND my autobox slides straight on..? This all sounds good to me...

l was worried my box wouldnt fit a bigger motor, but l am also a bit worried about my boxes condition. ln the summer when spending time in slow traffic, so lm guessing the oil in the box is getting hot, despite a nice big cooler rad, sometimes when changing from forward to reverse and back again, there is a delay once its been selected...then it sort of lurches once it starts moving...this doesnt happen often but does worry me a bit..? Should l stop worrying..? Any ideas..?

Thanks again for your time...much appreciated...Bazza

The only thing you need is the crankshaft spacer (shown in one of the pics) as the 4.6 crank has a longer nose. And you might need to recess one of the cross-bolts depending on the oil pump (I think a standard pump is OK). But apart from that, it's a straightforward buildup.

Dunno about the autobox probs - what sort of box is it?

Chris.

I have a new TH350 3 speed box for sale that has been uprated to over 450bhp that will fit the 4.6 with the adaptor plate I have if you want to change to Chevy transmission!!
Just a thought. I'll stick it on Ebay in the new year as a conversion.

ChrisJC wrote:The only thing you need is the crankshaft spacer (shown in one of the pics) as the 4.6 crank has a longer nose. And you might need to recess one of the cross-bolts depending on the oil pump (I think a standard pump is OK). But apart from that, it's a straightforward buildup.

Dunno about the autobox probs - what sort of box is it?

Chris.

Hiya Chris, where would l find any ID marks..? Heres a couple of pics...maybe it might be obvious to someone what gearbox l have..?





Can anyone tell from them..? Or do I need to do some closer/better ones..?

Thanks............Bazza

mgbv8 wrote:I have a new TH350 3 speed box for sale that has been uprated to over 450bhp that will fit the 4.6 with the adaptor plate I have if you want to change to Chevy transmission!!
Just a thought. I'll stick it on Ebay in the new year as a conversion.

Hiya Perry, that sounds very interesting..... Is it any bigger than a british one, physically on the outside...? I havnt got a lot of space to play with as you can see from the above pictures..

Bazza .........

Engine number is on a little tab near the dip stick

I can't identify that box - all I can say for sure that it is NOT the ZF4HP22.
But I'm sure somebody else will identify it.......

Chris.

P.S. Like the trike!

Thats definetly a Borg Warner 65 or 66 box, u can tell by the servo's on the side of the box, an almost direct replacement would either be the GM180 again a 3 speed box, or the zfhp22 as chris recomeds, in fact i don't think there's that much diffrence in length, just a much larger bellhousing, photos on my webshots if u need a look, john