Borg & Warner 4-Speed Manual Rebuild

[johng]

Good progress Andy, hopefully it will all be done for the Museum of Power

 

[Forrest Gump]

Continuing…. The gear selector arms / detent assembly is fitted in the side plate.





Finally the side plate is sealed and bolted on. With a spanner on the selector arms I can try changing the gears….they seem to all go in okay.

I‘m going to fit a Hurst shifter to try and improve the gear change experience. The old stock shifter wasn’t too bad generally but occasionally did a bit of a weird thing where it felt like the blades in the mechanism missed the levers, probably wear and abuse.


Unlike the stock gear-lever assembly that is mounted to the car, the Hurst mounts on the gearbox which has got to be better. It’s nice to be able to set it up on the bench, getting the rod lengthsadjusted just right.


There we go, I can now do some gear changing. This feels very solid and positive, no play anywhere.
I just hope the gearbox works when I get it back in the car and road test it.


I must remember to add the oil!
Im going to try this GL4 oil from “Driven”. The application notes actually state it is perfect for a Super T10 gearbox. I keep seeing this Driven oil being used here and in the US.

 

[Oneball]

It’s not easy to get the box back in with the Hurst attached, I put mine in after the box is in.

 

[Forrest Gump]

It’s not easy to get the box back in with the Hurst attached, I put mine in after the box is in.

Okay, I did wonder how do-able that was going to be. Were you putting the box back with engine still in situ, or as I’ll be doing with engine and box going back in together?

 

[Oneball]

Okay, I did wonder how do-able that was going to be. Were you putting the box back with engine still in situ, or as I’ll be doing with engine and box going back in together?

I’ve done it both ways. The problem with the hurst is the sticky up bit makes it difficult to clear the gearbox crossmember as it hits the top of the tunnel. You can just do it if you put it in 2nd gear first but it’s a right fiddle. It’s pretty easy to bolt in the hurst after the box is in.

 

[Forrest Gump]

I’ve done it both ways. The problem with the hurst is the sticky up bit makes it difficult to clear the gearbox crossmember as it hits the top of the tunnel. You can just do it if you put it in 2nd gear first but it’s a right fiddle. It’s pretty easy to bolt in the hurst after the box is in.

Thanks, I’ll take it off and avoid that snag.

 

[CaptainK]

Gotta love a Hurst - I have one in my car too.

 

[Roscobbc]

The additional 'thing' to improve gearshifting 'feel' (not that it perhaps one would think it would make a difference) is to upgrade the front engine mounts to 'poly' - helped to tighten the shifter and driveline 'feel' up on mine.

 

[Forrest Gump]

The additional 'thing' to improve gearshifting 'feel' (not that it perhaps one would think it would make a difference) is to upgrade the front engine mounts to 'poly' - helped to tighten the shifter and driveline 'feel' up on mine.

I already have poly engine mounts fitted. They’re so solid I can’t imagine they give much cushioning from vibration!

 

[Forrest Gump]

An update on this project which has dragged on a bit due to various reasons (holiday etc).

While the engine is out I have fitted a new oil pan. The previous pan, as well as having a slight leak at the gasket joint in one spot, had suffered some corrosion and also rather embarrassingly, a nasty dent done by me!
I‘ve tried replacing an oil pan with the engine still in the car before - Not a very nice job with awkward access, gravity against you and really difficult to ensure you don’t get a leak. With the engine out of the car and upside down on the engine stand it’s all very much easier. I’ve chosen a cast alloy oil pan (Summit Racing) this time instead of pressed steel. Shiney isn’t really my thing but it wont be seen.
The pan went on nicely with a one-piece Felpro gasket. One thing I liked was the pan came with set-screw head fixing bolts (except the corner bolts). Getting a socket or spanner on hex heads is tight on some of the bolts normally.

 

[Forrest Gump]

The flywheel and clutch assembly are refitted then the re-built gearbox bolted back on. I fitted a new pilot bush into the back of the crank too while I was there.


The old GM stock shifter assembly has reached end of service on my car! I did like the old patina knob though (would have been black when new).

 

[Forrest Gump]

Engine and gearbox went back in last weekend.
It takes four gallons of anti-freeze to fill up, that’s a couple of quids worth.
Now ready for a fire-up and test run, I couldn‘t get the flippin engine to start! Misfiring and carb back firing. I had fitted a new set of plugs and HT leads so re- checked everthing, distributor went in and out a couple of times and eventually got it to run properly.

 

[Forrest Gump]

Finally ready for a test run on the road to see if the gearbox and Hurst shifter work.
On my driveway I could test 1st gear and reverse. Reverse goes in beautifully, that was often difficult before.
On the road the difference is night and day with the Hurst shifter - it feels very precise and seems to glide into gear.
The gearbox itself seems all good, no noises and changes gear nicely at any revs.


Then as I did a shift into fourth, the gear lever went loose…..aaahhh somethings happened.
I‘m stuck in third gear and several miles from home. If I can’t pull it out of third then there’s no way of getting any other gear. Luckily with V8 torque it’s not a problem only having one gear and I got back home okay in third gear.
A check underneath revealed the link rod has detached from the 3/4 selector arm. Pic below shows this with arm (blurred) at bottom of pic.
This was held in with a clevis pin and bush (both now lost). I’ll work out why this has happened today. Access is not great now it’s back in the car.
Other than this snag I very pleased with everything.

 

[Roscobbc]

And.......no doubt getting the clevis clip will be an issue?......what will you do? = find suitable washers and use an overlength split pin.

 

[Forrest Gump]

And.......no doubt getting the clevis clip will be an issue?......what will you do? = find suitable washers and use an overlength split pin.

I've just checked in the bag of left-over bits and fortunately there is one spare nylon bush and a spare clevis pin that I can use. I'm relieved that I didn't loose the rod itself or I really would have to mount a search!
I'll get under the car later and have a proper look but my feeling (looking at the spare) is that the clevis pins aren't quite the right shape and don't hook around the rod enough when they're in place. Hurst's buying dept probably found a cheaper supplier. I think I might have to take them all out and re-shape them a bit.
I think I trust a split pin more also, but that would probably need a washer next to it and there might not be room for one.

 

[teamzr1]

I think a Carter pin mounted from top down would be easier to do and be able to spread it apart to
assure not coming out on its own

 

[Roscobbc]

I think a Carter pin mounted from top down would be easier to do and be able to spread it apart to
assure not coming out on its own

What's a 'Carter' pin Jon?

 

[Alexm]

Hi Andy
Following your posts on the gearbox, noticed your electric fan.
I’ve just fitted a new alloy rad and 16” fan.
But someone at the nationals said I should leave the original fan and heat sensitive drive in as well ?
Would prefer not to use the old fan.
How is yours without it ?

 

[Forrest Gump]

Hi Andy
Following your posts on the gearbox, noticed your electric fan.
I’ve just fitted a new alloy rad and 16” fan.
But someone at the nationals said I should leave the original fan and heat sensitive drive in as well ?
Would prefer not to use the old fan.
How is yours without it ?

Hi Alex

I've never had a problem with just the electric fan, and have driven in heavy/town traffic on very hot days (35 deg) . It is a powerful Kenlowe fan though, and with no shroud either you'll notice. I did try a shroud once but found that made the car run hotter at normal speed due to restricting the airflow through the rad.

Have you got your dashboard back in yet?

 

[Oneball]

Looking at your photo, your clips don’t go in as far as mine. The hook shaped bit sits against the straight bit, if that makes sense.