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H151F manual gearbox rebuild

Fussy? Nah, I just object to spending money on a mobile skip. All I want is good enough. Not looking for perfect. Everything I have seen has been a dog and not as good as my beaten up machine. Have driven some manuals with shocking boxes.

Chris
 
1st test drive this morning and this rebuilt box works as it should and doesn't do anything it shouldn't :icon-cool:
 
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Did i actually miss a post saying it was going in??

Well done lads. When do you want these 10 to do :lol:
 
A brief summary;-

1. If you know your box has not been apart take plenty of pics.
2. Remember that the fork/syncro rings can go either way round on their hubs but only one way is correct.
2. The hubs can go either way round on the shaft but only one way is correct. The giveaway here is that one side of the hub has a recess in the splined area.This goes onto the shaft first to give a better leed on.
3. The thrust washer with the shoulder is the one for reverse gear.
4. Use 2 people to press pieces on and hold pieces in place. The multi plate syncros need to be spun to drop the 3 pegs into the gearwheel and then again to engage the second brass ring. Then the gearwheel needs to be held so that the cutouts in it line up with the sliders in the synchro hub.

Gearbox removal----what they forgot to tell you.

1. Drop the pipe off the exhaust manifold.
2. Take the fan off. Even after this when tilting the engine keep checking it as it jams up.
3. Take the transfer box off.
4. Support the box on a trolley jack but also have a 3x2 timber tied on the chassis rails beneath the rear of the box.
5. Tie a 3x2 timber on the front suspension arms as far forward as possible.
6. Other things removed it is now possible to drop the box down at the rear so it rests on the rear plank. Now it is possible to rotate it and pull it so it comes off without falling on you. Also gives much peace of mind. The jack is really only to jiggle the box about.
7. On putting back in remove the starter stud and when ready fit this back in from the front with a couple of lock nuts on.
8. Put the box in 5th gear. This way if the splines do not line up you can turn the output shaft and the box should shoot in. Then make sure there is a parrallel gap all round between bell housing and engine so that the final push will push the input shaft into the crancshaft bearing. Another push should see it all the way up to the dowells or beyond.

Whilst it is easier to take out and install with 2 people I managed to take it out by myself and put it back in. But when Jon helped on other occassions it was much easier.

I think that is all except Jon may see a few gaps I have missed and can fill in.

Always here to help
Frank
 
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Strange that this thread approaches it's conclusion just as the life of my gearbox has reached the conclusion of it's life.

Karl you have a PM.

regards

Dave
 
Hi Frank, 230+ thousand, started with a vibe before xmas, checked the usual culprits UJ's ect and could not confirm where the vibe was coming from. All oil levels good and no signs of leaks, vibes turned to sounds when in neutral and coasting. Pulled alternate props and drove with DL engaged ect again no change. Put it down to something in the gearbox, I have not been able to do to much as I have a dodgy leg at the moment, anyway today I drove it a little harder than usual and this showed a lot of noise (slipping gears) in the gearbox, checked VC as well and all good.

So as Karl has sent me over stuff to Spain where I live I am waiting for him to give me a price on a good box if he has one, failing that I will strip and rebuild my own one.

Also just realised I must have a setting in my profile wrong as your post was not flagged in my emails which I only just checked.

regards

Dave
 
The rebuilt gearbox has now done 170 miles and the gearchanges are very good. After cawling underneath after a long journey the other day it was just warm to the touch so there was no worrying friction inside. Today, as a final test, I drained the oil and it came out quite clean. As a conclusion this project has been a little tricky with lots of places for one to make mistake but we managed to rebuild the box and get it right without having to take it out to correct. So it will be staying in permanently and I have my very good original gearbox as a spare with only 134,000 miles on it. It's been an extremely rewarding and interesting project both enhanced by the fact that it's a second car so no pressure to get it back on the road.

Approximate times needed:-

Take out 6 hours
Clean strip and rebuild 15 hours
Install 6 hours

I'm sure Jon will correct me if I'm miles out on the hours as I wasn't really keeping count.
 
Sounds about right on the hours Frank. The gear change is very nice and has really bought that box back from the dead albeit with quite a bit of time and money spent.
 
Well I've got about as far as this, but probably heading back now. I know my limits. Hoped I might spot something really obvious like a wobbly bearing, but can't see anything out of the ordinary.

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Chris I might have said in my mail to you the box is not in use in Top Gear. I should have said 4th Gear as Top is overdriven on these new fangled things.
 
One thing that wasn't mentioned in the thread Frank was the presence of the two tiny dowels in the oil pump fillter. These looked very much like the oil pump drive dowels which are magnetic. How the heck did they end up in there and did you (Jon) put them back on the main shaft?

Edit - just found where Jon put them back in
 
They ended up in the bottom of the box because that's where the previous professional had left them.
 
Wonder how essential the oil pump is then. Is splash feed sufficient?
 
Frank/Jon,

Brilliant post and has been most informative, to the point where I have attempted to rebuild my own gearbox. So far so good and after 360,000 kms it all looks quite good inside. I have a crunch into third so I'll be replacing the 3rd synchro set.

I have a question about the intermediate plate and the bearing that sits on the counter gear cluster (I think you called it a lay shaft). When you took that out and re-installed it Frank was it loose or did you have to use a puller to remove and the reverse to reinstall? The bearing casing has marks that it has been rotating inside the intermediate plate but the bearings inside appear to be all ok?

Regards

Ben
 
Hi Ben,

This is the bearing with the plastic roller carrier isn't it ? If so the carrier is in 2 parts and is meant to be split apart by hand and can then be snapped back together. After splitting it you can check the inner race, on the counter shaft, for pitting and wear and the rollers too. Obviously the outer race as well. I think I must have used a puller to pull the inner part of the race off the counter shaft. Don't pull on the plastic, split it in half and remove first. The outer race is a sliding fit in the centre plate so it could have been turning. This could have been caused by the bearing being siezed to some extent. Is there much play now between the outer race and center plate when the outer race is in ? You could just slide the outer race in by itself and see.
 
P.S. No, no need to use a puller on the outer race. Sorry should have read your question more carefully.
 
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