4 speed automatic....

[harvey]

Only fear I would have is how you prevent it engaging in 1st, 2nd or worse still, reverse gears.

Reverse is the only worry, and that was done by using a normally closed relay in the supply to the overdrive solenoid, which was tripped open when reverse was selected by a supply taken from the reverse light side of the inhibitor switch, so disengaging the overdrive unit. It had the option of overdrive in all forward gears, but in practice it was (and still is) just used in top. IIRC there was a warning light fitted after the relay just as a double check that the overdrive had disengaged in reverse.

[djw113uk]

Right, after much trawling of books and internet, regretfully what I had in mind was wrong and what I have been informed of today is correct.

I had in my mind that the BW65 was the one that had a removable bell housing, and that the BW65 was therefore the one to start with. Unfortunately it appears that dolomites were indeed NEVER supplied with BW35 auto boxes, and the BW65 is not the ideal starting point The BW35 does also have a removable bell housing, and its shape makes it far for readily adaptable to the 4HP22 gearbox.

So: 5 options:
1. try and find an auto (BW35 esk) bell housing which fits to the dolomite engine
2. try and fit BW65 bell housing to the 4HP22 box
3. see if manual bellhosuing will receive the torque converter and fot the 4HP22 any better than 2
4. create an adaptor to make the BMW bellhousing mate to the 1850 engine
5. give up

I am going to look at the SD1 autobox I have - thought that was a BW65!, and look at the BMW bell housing and front of 4HP22 gearbox and try and find some inspiration!

Thanks to everyone for all your information. I might be interested in borrowing that BW65 bell housing just to make sure its impossible if that is okay?

David

[wiggybum]

4. create an adaptor to make the BMW bellhousing mate to the 1850 engine

Don't give up. Anything is possible if you have the patience and access to the right tools and people, so I recommend you take a look at the work undertaken by a chap near me:





He's managed to mate an Alfa Romeo V6 to a Land Rover gearbox and fit it all into a Suzuki jeep. Have a look through his project and see how you feel:

http://forum.difflock.com/viewtopic.php ... 26f2e42fde

[djw113uk]

hmmm. I have a lathe and mill, but no 3 phase electric to run them yet! Also have a mig, and have welded mild (and stainless), but not sure if it will weld aluminium!! (different wire, gas and..... more skill I think!)

The BW65 from an SD1 has a nice circular flat face on the front, but it is about 2" larger diameter than the nose of the zf 4HP22. My BMW 320 torque converter is about 9.5" dia, so I need to see if this will fit into the BW bell housing (SD1 V8 bell housing is huge, so no use to me!) Oddly the front of the BW65 in your photo doesn't look anything like the BW65 off the SD1.

Just going to have to get the dolomite bell housing and work out if it will work or not.

If I could borrow just your bell housing to measure up and rule out or work with, that would be great. I promise not to drill, chop or modify it! I would rather not drag a whole gearbox about just yet if you are happy to remove the bell housing from your spare?

[djw113uk]

Harvey... I don't yet have a BW 35 and 65 infront of me to compare but why might the 65 be so much harder or impossible to adapt?

The engine end of both is irrelevant, and BW35 not applicable for dolomite. The BW65 I have off an SD1 has a nice flat flange - with just 4 bolts. They are wider spaced than on the 4HP22, but there are two rows of bolts on that, so I don't think it will miss by much. Is the depth of the BW 35 and 65 bell housings vastly different perhaps: So the input shaft is longer on the 65?

From what I have so far it doesn't look too bad.

You also might be able to help or advise: The dolomite torque converter has 4 mounting lugs to the flex-plate. The BMW has 3. Is welding extra lugs to the torque converter a bad idea due to the heat (I think that is how the stag conversion is done?), or just the risk of alignment? I guess drilling the triumph flex-plate will be easier, subject to the distance the converter needs to be offset away from the engine? The way the Torque converter is sat so far off the back of the engine on the range rover gives me hope!

[gmsclassics]

I have an 1850/Sprint auto bellhousing. This is 180mm deep between the faces. The top holes are 130mm centres, the lower pair, 210mm. Upper to lower are 177mm centres with the diagonals 242mm.

I understood that the 35 and 65 were both fitted to the big Triumph saloons at different times. As the Sprint gearbox housing is the same as those same saloons, the bellhousing for the 35 auto might not be that different. Having said that I've never seen the 35 autobox fitted to a big saloon.

housing1.JPG (109.14 KiB) Viewed 2192 times

housing 2.JPG (108.39 KiB) Viewed 2192 times

housing3.JPG (113.39 KiB) Viewed 2192 times

Geoff

[djw113uk]

That is a very good point If the dolomite sprint gearbox is the same as a 2000 gearbox, then if I use the manual sprint adaptor then the big saloon BM35 bell housing might fit. I think I have a BW35 for a saloon on its way to me, so we'll soon see!
Thank you.

[wiggybum]

That is a very good point If the dolomite sprint gearbox is the same as a 2000 gearbox, then if I use the manual sprint adaptor then the big saloon BM35 bell housing might fit. I think I have a BW35 for a saloon on its way to me, so we'll soon see!
Thank you.

You'll need something regardless as the starter motor is on the drivers side (offside) on the 6 cylinder cars whereas all Dolomites have the starter on the passenger side (nearside):



Have a look at how the Stag BW35 bolts up. The Stag V8 has the starter on the left too. A Stag BW35 engine plate may be what you need.