3.8L Series II w/ SC swap?

[thrashercharged]

So the 3800 FWD bolt pattern does not bolt directly to the 4L30e huh? Hmm - what bellhousing bolt pattern was on the 1st gen Troopers with the 2.8 V6? Was that a RWD pattern? I vaguely recall now - it's been a few years - that's why the 3.4L out of a F body was a popular swap (due to RWD) and not the FWD 60 deg V6's, right?

And the 3800 F bodies had a 4L60e with a removable bellhousing on them didn't they? Does our 4L30e have a removable or fixed bellhousing? So who makes an adapter to adapt between the GM FWD bolt pattern and the 4L30e? Cost?

The Northstars had a lot of head gasket issues and wouldn't they have the same bellhousing issue? Plus depending on the model year, most had the Siemans PCM and I don't know if anyone's reverse engineered that to program it.

The 3800 should fit better being smaller and it's durability is much better (once you address the intake issues on the L36). So just how weak is the 4L30e?

[Mile High VX]

So just how weak is the 4L30e?

I recall that it's only rated for 260 ft lbs of torque.

Numerous members here have had failures of this transmission so it has a poor reputation.

[thrashercharged]

Yeah, I know it's a weak tranny - I bought a 2002 Trooper with a bad tranny and haven't had time to dive into it yet - it's still parked at the shop.

So that 260 limit is just under the 280 ft-lbs output of the stock L67. I wonder what the Bimmer folks have done to improve the 4L30e. Once I have mine apart I guess I'll get a chance to see just how small the clutches and things are. But I'm not intending on ever putting slicks on a VX and taking it down the strip so the abuse shouldn't be as bad. I'm wondering if a shift kit and some higher friction clutches (don't know if Raybestos has any for this trans or not) and a bigger trans cooler will help it live.

I'm mainly interested in keeping the 4L30e just to make for an easier and cheaper swap and to keep the TOD as the TOD seems to be the heart of a VX. I assume the tailshaft of the 4L60e doesn't allow the TOD transfer case to fit?

[bartmanS4]

The 4L30e is a weak link but not necessarily because of it's torque rating. The failures seem to be associated with solenoids etc. I would highly suggest doing a 5 spd swap though and the AR5 is a pretty rugged option that allows you to maintain TOD.
The bolt pattern is 60^ GM for 4L30e and AR5.
Everything I've seen shows the 3800 using the same bolt pattern.
http://en.wikipedia.org/wiki/List_of...using_patterns

[thrashercharged]

"The bolt pattern is 60^ GM for 4L30e and AR5."

So wait, will the 3800 bolt up to our 4L30e or not? Someone said earlier in this thread that it would not and would need an adapter. I know the 3800 and 3400 (which is a 60 deg V6) - both are typically used in FWD vehicles - share the same bellhousing bolt pattern.

Solenoids have been a known failure item in earlier 4T65e too but I believe you can get fairly robust ones to replace with, so I'd assume the same for 4L30e.

I didn't know you could retain the TOD with the AR5 - that's the 5 speed used in later Troopers (1999-2002) isn't it?

So assuming that the 3800 will bolt right in, why hasn't this swap been done already? Is there a big issue with motor mounts or something? Seems the F body parts like exhaust manifolds should make this easy?

[bartmanS4]

So wait, will the 3800 bolt up to our 4L30e or not? Someone said earlier in this thread that it would not and would need an adapter. I know the 3800 and 3400 (which is a 60 deg V6) - both are typically used in FWD vehicles - share the same bellhousing bolt pattern.

I don't know for sure but everything I've seen as far as specs go says it should work. LeonR said it won't work but I don't know what info he's working with. He may be right though. I do have an AR5 bellhousing sitting in my garage. If I could find a L67 to test fit it to...

I didn't know you could retain the TOD with the AR5 - that's the 5 speed used in later Troopers (1999-2002) isn't it?

Yes, four that I know of have been done including mine.
http://www.vehicross.info/forums/sho...light=ar5+swap

So assuming that the 3800 will bolt right in, why hasn't this swap been done already? Is there a big issue with motor mounts or something? Seems the F body parts like exhaust manifolds should make this easy?

I think someone with an Amigo did it but no one has done this on a VX to the best of my knowledge. I suggest you do it and document it well so that when I do it I can learn from your mistakes.

[thrashercharged]

When I get around to pulling that 4L30e out of that Trooper I'll fit it to a L67 block and see if indeed they fit and take some pictures.

Do you or anyone already know of any fitment issues? Does the oil pan / starter clear or is that an unknown? Anyone already look at the width? Does it fit between the rails?

I suppose the AR5 does away with any tranny controls issues but I'd think the 4L30e and the 4T65e that the L67 came with are close enough so the L67 PCM can control the 4L30e with some wiring and programming.

The TOD has a controller completely separate from the engine/trans controls right? And so does the ABS? I'd assume all they really need from the PCM is engine RPM or something like that so that might be an issue. I wonder if it got this info via a CAN or GM ClassII bus or something? That'll be something to look into. I guess that'll be the only hic-up, the communication with the TOD/ABS stuff since the engine will not be running off the Isuzu controller.