Installing new clutchplate and pressure plate, gearbox doesn't fit anymore, HZJ75 4.2

[zijad]

Hi Guys,

Some weeks ago I found my clutch of my HZJ75 4.2 of 1995 was slipping, so I ordered a new clutchplate and pressure group and meanwhile demounted the gearbox.
Then I found that the clutchplate was still good, but rather greasy. So I looked further and removed the fly wheel and then found that the oil sealing of the krank shaft was not that good anymore. So oil came into the clutch house and that made the clutch plate to slip.
After fitting the new oil sealing, flywheel and a new top bearing, I started to install the new clutch plate and new pressure group. Since I did not have a pilot bearing tool to position the clutchplate exact, I used a similar sized(diameter) socket and then screwed the pressure plate into place. I then started to place the gearbox back in place, but then the problem came in. The final 3 cm between the clutch house and the engine couldn't get closer.... We tried lot's of stuff but it just didn't move the final 3 cm. We looked around the gearbox and we are very sure that it wasn't somehow blocked.

So now we have the question, how exact does is come when placing the new clutch plate and pressure group? My best guess is that it was 85%/90% accurate centred. Could this be the cause why the gearbox couldn't get to the engine the last 3 cm, in such a way that the input shaft was pressing the pilot bearing or the clutch plate?
Or do you know any other reasons what could cause this 3cm gap...?

Thanks for you help in advance,
Best regards,


Zijad

 

[StarCruiser]

Hi Zijad.
It can be tricky getting the gearbox back on even when everything's lined up 100%. If there's any chance it's misaligned then it's going to be even harder. If the splines of the gearbox don't line up then that can stop it, if the shaft then won't engage the pilot bearing because of misalignment then there's two places to stop it. I don't know how much misalignment can be acceptable but 10 - 15% sounds like too much to me. Worth buying or borrowing an alignment tool if you can. If not, perhaps using a bar or small socket in the pilot bearing wrapped with insulating tape to increase its size to that of the clutch splines MIGHT help it get closer to being well enough aligned.

Hope this helps, I know it can be a difficult job.

Richard

 

[24carrot]

hi have you tried rotating the gearbox to make the splines met

Sent from my SM-G920F using Tapatalk

 

[Trevor]

I've used studding that is put through the holes in the bell housing and engine to help me make sure I'm lining up properly, it's easy to get the gearbox tipping too far up or down which can make aligning tricky.

 

[clivehorridge]

Been there loads of times, several "T" shirts on this story.

IMO, drop the G/B off again and really do your best to better align the friction plate, better still, get an alignment tool to assist.

I used to use old primary shafts from broken G/B's and had quite a selection of common cars, many moons ago as a teenager when I was fixing friends cars on a regular basis.

Even when aligned, it's often a pain to get the splines aligned as well as the end of the shaft in the pilot bearing. Whatever you do don't force it but having some longer bellhousing bolts to bring the G/B up at the right angle can help. Use them for alignment NOT for forcing the belhousing home, then waggle the free end of the gearbox in a rotating fashion whilst putting hand or foot force on the bellhousing to insert the shaft. It will go eventually, but some can be very stubborn.

The worst one I did alone was a Triumph 2000 with a very heavy box (with overdrive) and it took me two days of swearing and pushing my guts out upside down. Totally exhausted I gave up and went for what must have been my 10th cup of tea.

After, I went back to the car, and first attempt it slid in place as if there had been no problem at all.

Luck of the draw... good luck.