Tips for reinstalling gearbox after a new clutch?

Tips for reinstalling gearbox after a new clutch?

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tux850

Original Poster:

1,728 posts

88 months

Monday 13th March 2023
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I’m in the middle of replacing the clutch on my Hyundai Coupe, and I really do mean the middle - on my second day now learning (and swearing) as I go along and I’ve got the engine and gearbox separated, old clutch off and new one ready to go in. Halfway point.

I feel like I am past most of the hardest bits, particularly removing seized bolts in awkward locations etc, working out what bolts are relevant and what aren’t, and whilst I am confident I can get the new clutch aligned and fitted okay I am worried about refitting the gearbox. I’m not the strongest but even weight aside it’s proven to be a right pain manhandling it around during removal and I am mindful (quite possibly unnecessarily) about causing damage to the new clutch whilst trying to push, pull, shove and generally abuse the gearbox back in to place - not to mention even getting the input shaft sufficiently aligned for it to even begin to think about going back in.

Any tips from others more experienced? I’m weighing up 1) just lying underneath (the gearbox is resting precariously on the subframe at the moment) and purely manhandling bench-press style into place, or 2) sitting it on a jack to take the weight and manhandling it in from there, or 3) getting my engine hoist out and suspending the gearbox from that adjusting it’s height and positioning before sliding it gracefully into place like an ISS docking.

Any thoughts/suggestions other than to stop procrastinating and overthinking things? What works for you?

Edited by tux850 on Monday 13th March 22:38

BananaFama

4,404 posts

78 months

Monday 13th March 2023
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I assume you have a clutch aligning tool , if it's not lined up the gearbox shaft is unlikely to ever go in .

I would also go with #2 or #3 as even with a perfectly aligned clutch plate gearbox rarely goes in first time and having to lower it back down onto your chest is unpleasant and could be painful ,i don't recommend that .

buggalugs

9,243 posts

236 months

Monday 13th March 2023
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I always did the wobbly balance on a jack thing. Clutch alignment tools are great although I always managed without one eventuality.

InitialDave

11,856 posts

118 months

Monday 13th March 2023
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If you have a hoist, yes, use the hoist to suspend it at the right height and wriggle it into the exact position. I've done the various approaches such as bench pressing from underneath, using a jack etc, and having it slung from something to take the weight but still free to move about is by far the easiest.

Doesn't need a hoist, though, another person lifting it from above with a strap is just as effective.

Darkslider

3,071 posts

188 months

Monday 13th March 2023
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Always get the clutch friction plate perfectly central before bolting the pressure plate down, I find a socket/drill bit etc the same diameter as the gearbox input shaft spigot that fitted snugly into the flywheel, then wrap a few layers if insulting tape round to step it up to the diameter of the friction plate.

Definitely support the weight of the box on something while you're fitting it if you can, they always take 5 minutes of wiggling, levering and swearing to go back on for me. Sometimes I give up and go and have a cup of tea, then when I come back and try again it just clicks into place perfectly leaving me wondering what on earth I was struggling with!

Bear in mind before and during refitting you need to check all your dowels and studs are present and in the right places, if any nuts came out with the studs attached then separate them and refit the studs first, it's a lot easier to guide the box over studs if there are any than screw them in afterwards!

Also give a good check all around the box before starting the tightening process, I've heard of more than one wire or complete loom being caught in between a gearbox and engine giving some interesting faults.

finlo

3,731 posts

202 months

Monday 13th March 2023
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Darkslider said:
Always get the clutch friction plate perfectly central before bolting the pressure plate down, I find a socket/drill bit etc the same diameter as the gearbox input shaft spigot that fitted snugly into the flywheel, then wrap a few layers if insulting tape round to step it up to the diameter of the friction plate.

Definitely support the weight of the box on something while you're fitting it if you can, they always take 5 minutes of wiggling, levering and swearing to go back on for me. Sometimes I give up and go and have a cup of tea, then when I come back and try again it just clicks into place perfectly leaving me wondering what on earth I was struggling with!

Bear in mind before and during refitting you need to check all your dowels and studs are present and in the right places, if any nuts came out with the studs attached then separate them and refit the studs first, it's a lot easier to guide the box over studs if there are any than screw them in afterwards!

Also give a good check all around the box before starting the tightening process, I've heard of more than one wire or complete loom being caught in between a gearbox and engine giving some interesting faults.
My mate managed to refit a cylinder head trapping his leadlamp lead between the head and the block!

tux850

Original Poster:

1,728 posts

88 months

Monday 13th March 2023
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Thanks for all the input - really appreciated. Looks like the hoist might prove to be the most sensible approach, not to mention safest as I’ll be working alone. I think it was mostly laziness me thinking twice about getting it out, and also thinking perhaps I'd spend longer building it then using it! I suppose I should view that as a good thing.

Thanks for the tips/warnings about things getting trapped - that's *exactly* the sort of thing that happens to me. Can almost guarantee it so it'll be more a case of what gets caught, not if!

Regarding alignment I bought one of these:



Testing it on the bench seems to suggest it being quite effective. It almost self centres, but can be adjusted and then tightened up to make what feels quite a secure positioning of the disc against the pressure plate.

Edited by tux850 on Monday 13th March 23:01

President Merkin

2,696 posts

18 months

Monday 13th March 2023
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That ^^^ will work fine. Lots of good advice so far. In the past I have used trolley jacks to lift boxes in & once even the long bar from a bike workstand & ratchet straps to winch it up into place. That worked surprisingly well.

One good tip - use a cable tie to temporarily lock the clutch release arm on the outside of the box. This will stop you accidentally actuating the clutch fork during refitting & potentially knocking the release bearing off its shaft. That would really spoil your day.

TwinKam

2,937 posts

94 months

Monday 13th March 2023
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I have a number of trusty old screwdrivers (Draper Ph3 & Pz3 with broken handles) that I use as guide pins. They have just the correct size shafts (8.5mm presumably) to pop through a bellhousing bolt hole and into the corresponding threaded bolt hole in the engine (M10 being a very common bell housing bolt size). It doesn't matter which holes you pick just so long as you consider first their removability when the 'box is fully home! I find these are most helpful, being long enough to get the 'box in line well before the input shaft is near the clutch plate, keeping the rotational position of the 'box steady, whilst still allowing it to slide towards the engine. You still need to 'take the weight' of the 'box, but its range of movement is limited to approximately where you want it to go. One will also provide a handy fulcrum to lever the flywheel around a few degrees around if I feel that the splines aren't lining up. Regularly check and adjust the squareness of the 'box's approach to the engine by gauging how parallel is the gap all round or how much of the ring gear eg is covered, and don't force it, it will just satisfyingly 'plop' into place eventually (if it is correctly aligned that is). Have a bolt to wind in immediately, because it will 'plop out' just as readily.
Good luck.

tux850

Original Poster:

1,728 posts

88 months

Monday 13th March 2023
quotequote all
This is great - thanks. Can’t beat the voice of first hand experience, and it gives me a lot more than Haynes saying ‘refitting is the reverse of removal’!

Good suggestion re the release arm - I’ll do that. This clutch is actually a pull type so once the gearbox is back on I need to lock the bearing into its circlip in the clutch with the arm so there’s no going back at that point, and that’s where I’ll be discovering a trapped harness or the suggested alignment screwdriver not coming back out so thanks for that warning too!

Edited by tux850 on Monday 13th March 23:13

SturdyHSV

10,083 posts

166 months

Tuesday 14th March 2023
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If you're really unsure, find out what thread the bellhousing bolts are, and buy some much longer ones from Amazon or what have you, ideally with a long smooth section like this:



Thread some through the a few of the bell housing bolt holes and in to the block. You now have a nice slidey support for the gearbox that will have it pretty well aligned right off the bat, once you get it seated, bolt in a few of the proper bellhousing bolts, and you're golden.

Would agree if you can get it supported from above that would be easier, and the 5 minutes it will take you to arrange will probably save you 15 minutes of swearing.

EDIT:

Oh and if you have any copper slip, give the alignment dowels (assuming there are some!) a bit of a brushing up and a bit of copper slip on them. Just makes it easier in future if it needs to come off again.

Krikkit

26,500 posts

180 months

Tuesday 14th March 2023
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I do the above, but instead of bolts I just use some threaded bar for a couple of quid - that way you can get the weight of the box on it and guide it home.

E-bmw

9,105 posts

151 months

Tuesday 14th March 2023
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Changed a clutch on a clio a few years ago & that had 3 (IIRC) long bolts that were long enough to do the full job without fully removing the box all the way off.

tux850

Original Poster:

1,728 posts

88 months

Tuesday 14th March 2023
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At this rate the gearbox is going to be installing itself! Thanks again for all the input - I feel quite confident now.

I'll go with the guide bolts idea and have ordered a couple of 180mm M12 bolts from Amazon which should be plenty long enough, and whilst they might be pricey at a fiver they could well prove to be really handy and I do keep reminding myself I'm saving hundreds doing the job myself.

Point noted re copper slipping the dowels - I have seen a couple so will do that for next time, which hopefully there won't be for some time!

paintman

7,669 posts

189 months

Tuesday 14th March 2023
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Krikkit said:
I do the above, but instead of bolts I just use some threaded bar for a couple of quid - that way you can get the weight of the box on it and guide it home.
^^^^ Exactly what I've done for years.

You just need a couple of short lengths & once the gearbox or transfer box are on them it's easy.

SturdyHSV

10,083 posts

166 months

Wednesday 15th March 2023
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paintman said:
Krikkit said:
I do the above, but instead of bolts I just use some threaded bar for a couple of quid - that way you can get the weight of the box on it and guide it home.
^^^^ Exactly what I've done for years.

You just need a couple of short lengths & once the gearbox or transfer box are on them it's easy.
This is a fair point, the benefit with the threaded rod is you can obviously thread it in and there's no 'head' to go over, so you can put the gearbox straight onto the threaded rods...

I actually did this myself when trying to install my gearbox at one point, I failed as the clutch alignment tool had 'sagged' a little (twin plate clutch) so the input shaft just wouldn't go in through the second plate, frustrating that was until I finally tried realigning the clutch again and found it practically fell together hehe

tux850

Original Poster:

1,728 posts

88 months

Wednesday 15th March 2023
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I suppose I cut cut the bolt heads off with an angle grinder to allow the box to slide over the end, and perhaps cut a slot too to ease unscrewing.

All set now, just need to wait for acceptable weather to align with when I'm free as for a while now we've been 180 degrees out of sync!

SturdyHSV

10,083 posts

166 months

Wednesday 15th March 2023
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tux850 said:
I suppose I cut cut the bolt heads off with an angle grinder to allow the box to slide over the end, and perhaps cut a slot too to ease unscrewing.

All set now, just need to wait for acceptable weather to align with when I'm free as for a while now we've been 180 degrees out of sync!
If you ended up down the threaded rod path, you can just put two nuts on and loosen one into the other. Once they bind up, you can then use it to loosen / tigthen the threaded rod.

tux850

Original Poster:

1,728 posts

88 months

Wednesday 15th March 2023
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Thanks, good tip. The bolts have just arrived (with our seemingly daily Amazom delivery!) so will proceed with those.

I'm probably at the point now where I've talked longer about the job than it'll actually take me! Of course, there's always the possibility of my crane collapsing and the overly long bolts being unable to take the weight of the gearbox and snapping inside the crankcase. Will start another thread seeking advice if that happens. biglaugh

Pica-Pica

13,621 posts

83 months

Wednesday 15th March 2023
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I appreciate all these tips and experiences on here. They just remind me of a job I have only done once (back in the 1970’s) and would never wish (and never needed) to do again.