The V8 Owners Forum -

I have an SD1 Rover with a standard 3.5 EFI engine - apart from a MegaSquirt. It's currently fitted with a GM TH 180 3 speed auto and I'd like something better. Like the ZF 5 speed auto in my other car. Sadly, Land Rover never fitted a ZF 5 speed, and the 4 speed they did fit fouls the bulkhead due to the deep bell housing. And I'd rather not get into modifying that.
So how about a GM 5 speed? The TH 180 has a removable bellhousing - does the GM 5 speed have this too? The ZF is an all in one casting. It seems to me it would be easier to modify a box where the bell housing detaches.

I realise there will be issues with an electronic control box - but at the moment I'm more concerned with the mechanical ones.

You could get a car version of the ZF4HP22 with a different bellhousing and make an adaptor plate up. Or just get a different bellhousing and stick it on a Sherpa 4HP22 so you get the 2WD with the right valving for the V8.

The bellhousings are interchangeable on the ZF4HP22.

Chris.

ChrisJC wrote:You could get a car version of the ZF4HP22 with a different bellhousing and make an adaptor plate up. Or just get a different bellhousing and stick it on a Sherpa 4HP22 so you get the 2WD with the right valving for the V8.

The bellhousings are interchangeable on the ZF4HP22.

Chris.

Thing is I'd like to go to a 5 speed anyway. How do you actually make sure the 'box is centred properly if using an adaptor plate? And how thick would it have to be?

BTW, think a RWD tailshaft can be fitted to the Rangie ZF. Not sure if this involves changing the mainshaft, though.

Dave,

There an interesting thread running on the British V8 forum (in the USA) at the moment, this one mainly re fitting a 5 sp modern auto box but there are other american boxes that can be made to work such as the TH200R but that Lexus? box Jim B is talking about is very interesting and quicker than you can change manually.

http://forum.britishv8.org/read.php?6,15171,page=1

You will find the guys very helpful re matching up bellhousings to mate to a Rover V8 as a lot of the guys run them and Buicks which have the same bolt pattern.

The TH180 is a presumably an american box so you might get lucky and be able to use the bellhousing with a later GM box.

Kevin.

CastleMGBV8 wrote:Dave,

There an interesting thread running on the British V8 forum (in the USA) at the moment, this one mainly re fitting a 5 sp modern auto box but there are other american boxes that can be made to work such as the TH200R but that Lexus? box Jim B is talking about is very interesting and quicker than you can change manually.

http://forum.britishv8.org/read.php?6,15171,page=1

You will find the guys very helpful re matching up bellhousings to mate to a Rover V8 as a lot of the guys run them and Buicks which have the same bolt pattern.

The TH180 is a presumably an american box so you might get lucky and be able to use the bellhousing with a later GM box.

Kevin.

Thanks for that Kevin - they seem to have as many answers as I have questions.

Cost is of course an issue - as is bodywork mods, as I don't have a garage, and don't want the car disabled for long periods. So my ideal would be to modify whatever ready to swap.
GM went out of favour with UK makers - for example the first 4 speed Vauxhall used was an Aisin Warner. So later ones aren't going to pop up often in breakers.
Ideally, I'd like to use a 5HP18 since I know and like it. Cheap secondhand - I already have one, and it will fit the transmission tunnel. After market ECU available. But it's marginal torque wise for the RV8, and has a one piece casing.

But if a GM 5L40E would fit the 180 bell housing easily, it might be worth searching one out.

I had a 5HP24 from a BMW540 for sale until very recently... Big old thing though.

Eliot wrote:I had a 5HP24 from a BMW540 for sale until very recently... Big old thing though.

Yes. Think it can handle the largest engines. The 5HP18 is not much larger than my current 3 speed GM - and looks like it would fit in the available space. I believe they can be beefed up too with stronger clutches.

Then I guess it depends on the power output of your engine, how you program the box and how you drive it.
As its electronic, you can raise the line pressure a little bit (10-20%) and reduce the shift times to give a firmer change which is easier on the clutches.

the box will take around 228ft-lb so, not a million miles away from the output of a rv8.