Engine and Transmission Tech

Jim, what is the hole diameter? Fitting the A761E to that bell might be pretty easy. To go from SBC to BOP is not hard. Edith's V6 Buick (TR7) is mated to the 700r4 with a simple 1/8" plate and even that may not be necessary as I'm quite sure that 4 bolts out on the bellhousing flange is enough. I suspect they just wanted to cover the hole at the top. I'll take a closer look first chance I get.

JB

I don't know the diameter, this is the only picture I could find of the older Chevy V8/4.3 V6 pattern. Those other pictures are of LS version which look close but is deeper and extra bolt hole on top. It looks like a dual bolt pattern ring between the bellhousing and tranny might work.




Edited 2 time(s). Last edit at 03/27/2010 08:53PM by mgb260.

Jim's and clan. 94-97' Camry and Lexus 300, anybody ? Need tcm ? Hop-up parts ? 4 spd. od. ? Nippon has em. My BH. "may" machine to fit. Thanks, roverman.

Art, my apologies, but sometimes I just don't understand you. Are you suggesting I use a 4 speed transmission instead of the A761E six speed I just bought? Or something else entirely? I'm just a little slow to catch on sometimes.

The news on a controller is mixed. So far I've not found a suitable TCM, although a possibility exists that the late model Toyota Avalon *MIGHT* use a separate TCM. I plan to check with the dealer but I'm not holding my breath. Meanwhile, the MegaSquirt has some potential. Using it's GPIO board (General Purpose In/Out) add on which connects using CAN bus architecture, the guys have been using it to run GM and Ford 4 speed automatics. It has additional capabilities so the main limiting factors seem to be adding the code to run the extra 2 gears and implementing pulse width modulation on the outputs to control shift firmness. neither seems to be insurmountable, provided I can get someone familiar with code to help out, and I already have the MS controller for the engine so I'm part way there anyway. This is handy since MS can also do things like retarding ignition timing when shifting and control the lock up clutch during a shift based on operating conditions. So in a perfect world things will be great! Wonder how close reality can get? I need to find a real good service manual on the A761E.

Nothing new yet on the bellhousing, I've been tied up with vehicle and tractor maintenance and haven't been able to look at it. But the warmer weather coming up should help.

JB

Jim, Has the GPIO system been used for transmission control before?

It has been a while since I looked at the MegaSquirt system. I didn't realize they were using CAN hardware, but I shouldn't be surprised because their philosophy has been to use non-proprietary standards.

Jim B. and clan. I'm sorry, I was considering an A541, for my own use, easy to get, here. Just trying to get more info on hop-up/etc. I haven't heard back from "trans tek"?, yet. Little B.O.P.'s came with 2and3 spd. autos, that were problematic. Didn't mean to jack your thread ? roverman.

That's OK Art, Jim Nichols is also using a similar tranny, I forget the exact number, A340 maybe? Anyway they're all in the same family so I really don't mind at all as long as I can keep from getting confused. Paul, I think they've been using the GPIO board for a year or two now and they have a pretty well developed kit for it (MegaShift).
[www.msgpio.com]
Of course they were using a second MS board to do it before that so the development work has been going on for quite awhile. I think practically all of the work has been with the 4L60E though so I'm a little out of the mainstream. The good news is that the 4L60E uses PWM on one of the shift solenoids and also on the line pressure solenoid so it should be almost a cut-n-paste code mod. Plus the output for the line pressure solenoid could perhaps be used for one of the extra gears in the 761. I don't know yet how many shift solenoids it has, it's even possible that could be enough. The level of control in MegaShift is quite sophisticated.

Jim

Jim, Actually Jeep Cherokee AW4(same as A340) with either Isuzu V6 or Jeep Comanchee 2.5 bell(60 degreeV6/3800/4.9 Caddy) bolt pattern. Maybe you should take a look at the 92-96 Jeep Cherokee controller, I know it is for 4 speed but you may be able to modify.I found a 97 S-10 4.3 V6 (Chevy pattern)4L60E bell like in the picture on car-part.com for $65. I found lots of tranny's and bells like mine, but haven't had time,too short handed where I work.



Edited 1 time(s). Last edit at 03/31/2010 01:26AM by mgb260.

Some days are just better than others, I guess you have to grab on to the good ones and forget the rest. Today I learned my "6 speed" transmission is a 5 speed, and the junkyard guy is avoiding me. Just what I get for making a distant purchase I guess. So that created a detour and I'm back on the hunt for a 6 speed and will look more closely local. I can make someone a killer deal on a 5 speed though. I guess in the meantime it'll do for a mock-up. I know what you're thinking, why not just go with the 5? Yeah, I'm considering that too. Guess I could upgrade later.

Jim

Jim, Maybe get a partial refund . run the #'s challenged trans and save for what your "really lusting for", u-no, the (8) speed ? Meanwhile, you can put a nano-second, spark kill and fool the motor into thinking itsa 6 speed ? Good Luck, roverman.

Don't suppose you mentioned your professional status to ole "I got tons of six speeds" at the junkyard, did you? He should know better than to stick it to a barrister.

Rover bell for a ZF 4hp22

I seem to remember theres a GM180 option for the RV8, would that be any better for a Bellhousing,

Jim B., sorry for the thread jack.

I did a search on ZF 5hpNN and 6hpNN and made some interesting discoveries.

The 6hpXX transmissions have integrated bellhousings.

The 5hpXX transmissions seem to be very similar to the ZF 4hp22 transmissions used on Rovers. I suspect that it is possible to bolt the Rover 4hp22 bellhousing on a ZF 5hp24 or 5hp30 to get a narrow case 5 speed auto that fits the MGB.

As in Jim's case, the challenge will be the electronic controller for the transmission.

Very interesting stuff guys, can we get some more detail shots maybe?

Finally got a reply from Michael today, after I mentioned I might be interested in an 8 speed. (Funny how dollar signs can affect a guy's attitude ;-) ) Actually he's not a bad guy and I didn't mean to be critical. To be fair it's a mistake that anyone could make. Lexus used both the 5 and 6 speed in the SC430 and changed over mid year, plus they both look exactly alike as far as I can tell so you have to cross reference the part numbers. Plus he gave me a killer deal on the 8 speed. It's more than I've ever paid for a tranny in my life, but it's less than half the going rate so I'm pretty psyched.

Anyway, the upshot of it is that we made a deal on an 8 speed out of a 2008 IF-S. This is the transmission that is second in speed only to the transmissions used in F1 cars, which shift in .05 seconds. This one is half as fast at .1 sec but that's still faster than you or me. They also keep the converter locked in the top 7 gears so it acts more like a standard transmission, and there are a few other tricks. But I don't plan to use the Lexus computer to run it, I want to use the Megashift add on to the Megasquirt controller I already have.

So now the dilemma. Do I put in the 5 speed first for the simple install in order to get the car on the road faster, or do I go for the whole tamale? Not a bad choice to have to make, everything considered.

JB

2008?,Man, it's probably just broke in. If you got an older one like me, you would have to decide when you rebuild it. Parts prices bring up the costs quite a bit on a "good deal".

8 speeds...how many overdrives?

8 speeds! We'll have to start calling you "shifty" with that one in the car. As for which to install, what's your estimate on development time? It sounds like the basic shifting controls will be pretty much the same for either, just have to add more levels for the 8 speed, I woundn't think it would take that much longer to get it programmed than the 5 speed. Either one will make the car very interesting to drive with great performance.

Probably granny low in first and top two Overdrive? Let us know when you find out the ratios,just curious.

1
4.596:1

2
2.724:1

3
1.864:1

4
1.464:1

5
1.231:1

6
1.000:1

7
0.824:1

8
0.685:1

R
2.176:1

JB