Team MightyBoy

Hey guys, I'm hoping someone on here knows their auto trannys, I've got 2 'Boys ATM both F8Bs & both autos & the transmissions have slight physical differences, 1 has Type D cast into the top of the housing & the other doesn't.
I'm thinking one might be the original 550 trans & the other is an 800 job, I'd like to know which is which & what the differences are ( I assume the gear & final drive ratios will differ) so I can decide which one to go with.
One isn't running & I've only driven the other one up & down my driveway (not reg'd yet) so I can't compare the 2 on the road.
Thanx in advance.

I've been mucking around with auto boxes for a little while and the only way I could differentiate the two was by counting the teeth on the crown wheel. Type D just refers to the Dextron fluid required. Like the manual box The F8B box has a noticeably taller final drive and therefore makes cruising a lot easier on the motor. The diff is interchangeable.

Cheers Brayden, I had a bit more of a search around the forum & found a thread from 2005 that makes it look like the trans I have in my Black 'Boy is from the 800 & If the final drive ratio is taller than the 550 trans I'll leave it right where it is.

So some 800/Hatch trannys have the Type D on top too?

I haven't got the Permit Inspection done yet so I haven't taken it out on the road for a good spin, what sort of RPM should I expect at 100 km/h when I do?

Is the final drive ratio taller or shorter on a manual box?

Thanks again.

I haven't hooked up a tacho to my auto MB yet, but going on sound the RPM for the auto vs manual seem to roughly correlate across 550 and 800. I have to admit that an auto F8B with matching box is a surprisingly nice package considering the auto 550 is a complete bucket of pus!

Brayden wrote: I have to admit that an auto F8B with matching box is a surprisingly nice package

Well after driving the 'Boy around for a few days I'd hafta agree with you there Brayden, it's got enough acceleration to keep up with traffic off the line & it will sit on 100 km/h without sounding like it's going to burst - I'm quite impressed.

While we're on the subject, I wrecked my white 'Boy & sold the transmission ECU under the passenger's seat because the auto in my black one is working fine but I just realised the black one doesn't have one at all
Can anyone shed some light as to why this is? Or is it hidden somewhere else?
Going by info gleaned from this very forum, I'm pretty sure the white 'Boy had a 550 trans & my black one has an 800 trans, is the ECU only fitted to the 550cc chaps?

ECU is fitted to both, and is identical.

good evening turbokat,
you wouldn't have a set of roof rails off the wrecked boy you are willing to part with would you.

thanks
darryl

I don't want to hi jack but dose anyone know if the diffs are also interchangeable from auto to manual?

if you mean the driveshafts, then yes

no I mean the differential.
im struggeling to find an auto box and I think its just the differential that's gone on mine (admitedly I have not took box apart to find that out)
so I wonderd if I could get a manual box and change diffs over.

The diff is completely different. A diff is unlikely to fail on an auto box unless the bearings collapse because it never sees any shock load.

G'day gents,
I have a 2 speed auto box out of a hatch / mighty boy in a miniature train. I am having some serious difficulties locating spares for it. The auto box is suffering badly from leaks around the bolts in bell housing and we have exhausted all known avenues for getting replacements. They are washers with rubber bonded to them with a conical shape that sit in a countersunk area around the bolt that then clamp up against the bolt when you tighten them up. I am hoping one of you knowledgeable folks will be able to steer me in the right direction for obtaining these parts.

Thanks in advance,
Briggsy

I've pulled down a few auto boxes, but can't say I noticed the washers you're talking about. Let me have a look at the spares I have and get back to you.

I have a couple of good second hand auto's if your still looking for one...let me know, cheers

mightyvitara wrote:I have a couple of good second hand auto's if your still looking for one...let me know, cheers

Most definately! How many have you got? What's the going rate? PM me if you like.

Briggsy