Hi,
My Muncie (I think) 4 speed gearbox has lost 1st 2nd and reverse - gear lever will only go forward and back to 3rd & 4th gear.I am considering swapping to a Tremec 5 speed for noise comfort at cruise speeds and fuel economy. Is this a fairly straighforward swap?
What engine do you have?
Bell housing adaptor required for your engine type. The prop will probably need shortening or new one.
The clutch will need updating if you have fork or hydraulic trust bearing type.
Also check the size difference of he bell housing. You will need to dial in it.
Quote from: JON1D on Jul 15, 2025, 05:24 PMWhat engine do you have?
Bell housing adaptor required for your engine type. The prop will probably need shortening or new one.
The clutch will need updating if you have fork or hydraulic trust bearing type.
Also check the size difference of he bell housing. You will need to dial in it.
Thanks, its an SBC 350. I had heard about having to centre the bell-housing - maybe a job for a pro
If you can use a dial gauge indicator and have a good magnetic base you just need to first confirm the run-out is within Tremec's tolerance of 0.005 thou. If not then you will require off set dowel pins to centralise. You half the measurement to shift the high to low point of the circle. Some bell housings required a dial plate that is bolted to carry out the alignment.
Lots of options with Chevy 350.
Quote from: JON1D on Jul 17, 2025, 03:56 PMSome bell housings required a dial plate that is bolted to carry out the alignment.
You can also split the front off the gearbox casing and use that, at least for Chevy engines where the 'nose' is shorter. T56 w/ Ford nose requires quite the springy contraption of dial indicator holder to snake through the nose so I ended up buying an alignment plate after failing to get a decent reading using the front of the casing.
If anyone needs to borrow it and can collect, you're more than welcome. It's (probably) a one time use thing for me!
Oh, other than offset dowels you can also open up the dowel holes on the bell housing and use weld-on collars if you have a steel bell (which is what I did) rather than offset dowels. With a cast bell you have to use offset dowels.