Transmission Rebuild DIY?

[ROADSTR6]

How hard is it to rebuild the transmission in a 4 synchro box no overdrive? Any special tools required? I found a needle from a bearing in my gear oil when I drained it. I'm doing a total restoration, so the motor and tranny are coming out anyway. Anybody done their own tranny rebuild? Kit is around $200.00 from Vicky Brit.

 

[Dave Russell]

It depends on how skilled you are at complex mechanical tasks. There are about 200 parts that have to go back in the right places, right sequence, & correct orientation. There are snap rings & retainers that you will need some tools for. The spring loaded bits often fly out before you have a chance to see how & where they were. With a very good shop manual & the time, patience, & observation skills, you could probably do it.

The needle bearing is not likely to have come out on it's own. Likely it was left over or left out by someone else during previous work. If it was left out, there will be future trouble. If it was an extra it will do no harm.

It will be a real learning experience & provide satisfaction if you succeed.-- Otherwise?
D

 

[Kimberly]

Rebuilding a standard four speed is usually not worth doing. There are lots of good used ones available. Check the autoist, he may have a few

 

[703MGB]

I am having an overdrive MGB tranmission rebuilt now.

The Tranmission rebuilt excluding the overdrive is really not expensive. The shop is charging me 5 hours work at 40$ CDN an hour + parts. That is not expensive...

I am very handy but I will not play in a transmission with all those clearances and parts flying all over the place.

If you are looking for a challenging project that will certainly fit the profile.

 

[dklawson]

Transmissions are only intimidating because of the number of parts. That said, I've had mixed results rebuilding them myself. Two turned out sweet and one needs doing again as I did not properly measure the synchro clearance on one of the gear hubs... the gear needed replacing.

As mentioned the special tools usually involve an assortment of snap ring pliers and a couple of things you have to improvise. You'll have to come up with your own method for compressing the detent balls in the gear hubs while you assemble them. Sometimes the laygear in the transmission needs an arbor to assist in assembly and these need to be borrowed or made.

It's not rocket science or anything. It's careful observation, taking notes, and careful reassembly paying attention to clearances. I should also add that it needs to be kept clean, almost as clean as when working on brake cylinders.

 

[RF Thom]

RoadsTR6.

Tranny are straight forward, like fear of the unknown. Get some steel bar stock the size of the lay shaft about 1.5" long, you'll need two [2]. Fit them into the laygear end holes to hold the needle bearings in place while you are installing the main shaft. Then turn the tranny up-side-down, let the lay gear fall into place then insert the layshaft pushing out the steel spacers - makes the job real easy. Also I always replace 2nd gear synchronizer when I do a transmission and switch 3rd & 4th synchros.

Good luck if you do it yourself, if all else fails call me I'm in Niagara Ontario [905] 562-9117

Regards, Bob