auto gearbox for 4.6

AriesSnake · Post by **AriesSnake** » Mon Dec 24, 2007 8:12 pm

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

ChrisJC · Post by **ChrisJC** » Wed Dec 26, 2007 4:21 pm

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.

AriesSnake · Post by **AriesSnake** » Wed Dec 26, 2007 10:24 pm

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.

Post by **katanaman** » Thu Dec 27, 2007 12:17 am

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.

AriesSnake · Post by **AriesSnake** » Thu Dec 27, 2007 1:24 am

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

Post by **katanaman** » Thu Dec 27, 2007 1:46 am

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.

ChrisJC · Post by **ChrisJC** » Thu Dec 27, 2007 9:46 am

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.

AriesSnake · Post by **AriesSnake** » Thu Dec 27, 2007 11:41 am

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

ChrisJC · Post by **ChrisJC** » Thu Dec 27, 2007 4:57 pm

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.

mgbv8 · Post by **mgbv8** » Thu Dec 27, 2007 10:05 pm

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.

AriesSnake · Post by **AriesSnake** » Thu Dec 27, 2007 11:07 pm

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

AriesSnake · Post by **AriesSnake** » Thu Dec 27, 2007 11:12 pm

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 .........

JC. · Post by **JC.** » Fri Dec 28, 2007 6:12 am

Engine number is on a little tab near the dip stick

ChrisJC · Post by **ChrisJC** » Fri Dec 28, 2007 8:42 am

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!

JSF55 · Post by **JSF55** » Fri Dec 28, 2007 9:58 am

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