2.9 out & 4.0 In - Clutch / flywheel ?'s

Bobcat7 · Nov 10, 2008

I just grabbed a '92 sploder for the engine, wiring harnes etc. I have done a 4.0 upgrade into an ol' B2 so I'm OK with the nuts and bolts.

My question - Can I use the 5spd manual from behind the original 2.9 in my
'91Ranger SC with the original clutch/flywheel? It has the heavier front end (dana35?)and I don't know what the diff is between transmisions (Mitsub./Mazda) I read on a diff swap thread that the Mitsu trans won't hold up very well. Altho I am not the gear-head that I used to be and will just use this truck for a work vehicle.

Isn't there a 10 or 11 inch clutch upgrade?

Do I buy a used one and re-surface or just go new -flywheel, disc, press'plate

What about phasing/balancing? My old flywheel looked like you could put it on in any position - no balancing issues?

Thanks for your help and I didn't mean "gear-head" like it's a bad thing...

mjonesjr · Nov 10, 2008

Bobcat7 said:
Can I use the 5spd manual from behind the original 2.9 in my '91Ranger SC with the original clutch/flywheel?

You can, but don't expect it to last long. The 4.0's have the M50D-R1 manual transmissions behind them. The FM-146 your 2.9 has is a weak transmission compared to the M50D. The 4.0 will probably destroy the FM-146.

Bobcat7 said:
It has the heavier front end (dana35?)

You are correct, it does have the Dana 35 TTB front axle.

Bobcat7 said:
Isn't there a 10 or 11 inch clutch upgrade?

If you have a 2.9, it is a popular upgrade to install the 4.0 clutch system and flywheel. This will get rid of the 2.9's stock 8" clutch and upgrade it to a 10" clutch.

Bobcat7 said:
Do I buy a used one and re-surface or just go new flywheel

You can get a new flywheel for about $60. You would pay about the same to buy a used flywheel and have it resurfaced.

Always replace the clutch disc, pressure plate, and slave cylinder whenever you can. The slave cylinder is the weakest part of a RBV's clutch system.

Bobcat7 said:
What about phasing/balancing? My old flywheel looked like you could put it on in any position - no balancing issues?

The balancing is done via the harmonic balancer on the front of the engine. You can place the flywheel in any position without a problem

Bobcat7 · Nov 10, 2008

Wow ya gotta love the internet. I would have to spend 20 bucks in beer to get the same info that I got here in milliseconds.

THANKS!!!!

BTW I bought this Ranger five years ago and drove it for a year before the 2.9 ticking, lack of power, collapsed lifters BS made me park it. If I can only get 10mpg I might as well drive the F250. This spring I forced myself to pull the 2.9 out so there was NO chance of reviving it. Now with e-bay I found a sploder with a leaking fuel line for 150.00 less than an hour away and I havew a winter project. I am sure I will be asking more questions

TYHANKS AGAIN!!!!

mjonesjr · Nov 10, 2008

Good luck and nice find on the Explorer.

I wish I could find one so I can either swap in a 4.0 into my Bronco II or swap the drive train (lift, axles, etc.) into the Explorer.

rickcdewitt · Nov 10, 2008

you could prolly run the tranny for a while if you aren't trying to powershift or burn out with it.but the 2.9 clutch would die pretty fast.i could get a new 8 3/4" clutch to slip with little factory tires and no load in the back of my ranger.

like jonesy said just swap it all out

BTW i get about 18 mpg's with my 4.0 swap,4.10's and 33" tires
and its a low oil pressure whooped pile of a rolled over motor

BlackBII · Nov 10, 2008

Yup, like they said, the FM146 wont last long, and neither will the 2.9 clutch.

I have run a 2.9 clutch and FM146 behind a 4.0 with no problems before for about a year, but it was babied and was a DD with 3.27 and 235's.

ghost_rader · Nov 10, 2008

just make sure you don't already have a m5od-r1 trans. i got a replacement for my 94 from the boneyard and it had a 2.9 bolted to it from the factory.

mjonesjr · Nov 10, 2008

The 2.9 M50D and the 4.0 M50D's have different gear ratio. The 4.0 M50D's are stronger.

fastpakr · Nov 10, 2008

No - they are NOT stronger. There is zero difference in strength between the two transmissions. The differences in the transmissions is purely in the gear ratio selection to optimize for the slightly narrower power range of the 4.0.

ghost_rader · Nov 10, 2008

i asked a trans builder who knows mazda transmissions very well, and he said the same thing

Bob Ayers · Nov 10, 2008

2.9 out & 4.0 In - Clutch / flywheel ?'s

Bobcat7

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mjonesjr

I dance with the Devil...

Bobcat7

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mjonesjr

I dance with the Devil...

rickcdewitt

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BlackBII

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ghost_rader

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mjonesjr

I dance with the Devil...

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