Gearbox removal

Gearbox removal

Author
Discussion

Gee Boo

Original Poster:

76 posts

145 months

Tuesday 22nd September
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Hi,my TVR 3000m 1978 is leaking gearbox Oil in generous quantities !! In the next few weeks I’m hoping to remove the whole gearbox/bell housing from underneath, there looks like there’s enough room but am asking if anyone has done this or attempted doing this ??? Please let me have your thoughts on this ?? Thanks for now , Gav .

nwarner

587 posts

218 months

Tuesday 22nd September
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When I took the gearbox out of my 3000S I took it out attached to the engine. The gearbox is heavy and I didn't fancy being stuck underneath with the gearbox on top of me. If you've got a lift etc. it might be easier.

Nige

Gee Boo

Original Poster:

76 posts

145 months

Tuesday 22nd September
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Thanks for your reply,yes I take your suggestion of wrestling with the gearbox under the vehicle isn’t the safest thing to do but feel if it can be removed from below it would be more simple ??? Has this been done by anyone...??

GAjon

3,237 posts

171 months

Tuesday 22nd September
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Yes it’s possible. I use a trolly jack under the box to hold it, secure the engine it’ll want to tilt back on its mounts, pull the box back to withdraw the shaft then lower the Jack and roll it out.

phillpot

15,965 posts

141 months

Tuesday 22nd September
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Must have changed dozens of clutches that way when I was in the trade, anything from little Escorts to Transits wink


You will need four decent axle stands to get the car high enough to lay under the gearbox and it's a kind of pull it back and controlled drop onto your stomach, wriggle out from under neath it once its out and drag it from under the car. getting it back in is the reverse smile

Some what more recently I've had the gearbox out of my S Series, that is a tight fit and not the lightest of gearbox's (or I'm get weak in my old age), but same method, one man job.

Gee Boo

Original Poster:

76 posts

145 months

Wednesday 23rd September
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That’s great to know it can be done !! Thanks for replying to my post ! In the next few weeks I’ll get on this and sort these leaks. Thanks again !

GAjon

3,237 posts

171 months

Wednesday 23rd September
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Check the seal and wear on the prop shaft spigot, it’s a common area for leakage.

Gee Boo

Original Poster:

76 posts

145 months

Wednesday 23rd September
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Love the comment about dropping It onto my stomach!!!!! Can’t wait to crack on !!!

Gee Boo

Original Poster:

76 posts

145 months

Wednesday 23rd September
quotequote all
GAjon said:
Check the seal and wear on the prop shaft spigot, it’s a common area for leakage.
OK, I’ll check that, a good friend of mine (Craig) is very knowledgable on this kind of thing and will be looking over my somewhat basic shoulder!!

phillpot

15,965 posts

141 months

Wednesday 23rd September
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Gearbox's generally only leak from the input or output, if it's leaking that bad it should be pretty obvious where it's coming from?

Rear seal can be done in situ.

plasticpig1972

70 posts

4 months

Wednesday 23rd September
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Where the Prop Shaft slides into the Gearbox is there a "Welch Plug" in the Prop Shaft.
On some Ford this can get knocked out or fall out which causes a big Oil leak.
Remove Prop Shaft and check this first.
Alan

TwinKam

1,505 posts

53 months

Wednesday 23rd September
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Gee Boo said:
Love the comment about dropping It onto my stomach!!!!! Can’t wait to crack on !!!
Yes, I wouldn't advise letting it drop on to anything laugh ...use your bent legs as a hoist, supporting it on your knees, gently lowering the bellhousing onto the ground between your legs whilst you're holding the tail.

V6 Pushfit

15,717 posts

68 months

Wednesday 23rd September
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A gearbox isn’t the easiest thing to get back lined up and on again. Be wary to withdraw it horizontally not to let the input shaft move the clutch or you’ll have to re center!

Gee Boo

Original Poster:

76 posts

145 months

Wednesday 23rd September
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Thanks everyone all this is great advice that’s very much appreciated

Stigproducts

1,309 posts

229 months

Wednesday 23rd September
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I did this on my M series gearbox inc bell housing (OD version). Some recollections that might help you

1. Once I got them separated from the engine I discovered the car wasn't jacked up high enough to get the bell housing out. It has to be at least a bell housing high off the ground, of course! That makes it a long drop too, when you get it unbolted it starts off pretty high up. I had to lie under the car and split the bell housing and gearbox, then turn the bell housing over to get it out. I couldn't jack the car higher- see point 2. All the time while the engine threatened to hit me on the head- see point 2!

2. When the engine is no longer attached to the bell housing and gearbox, there is nothing holding it to the car except the two forward engine mounts. That means it tries to twist and drop down because the rear half or it isn't supported. Sure, you can put a axle stand underneath it, but it has to be pretty high in the air (and therefore unstable) and (see point 1) that gap between the bottom of the engine and the ground where your axle stand is, is exactly where you would like to push your bell housing, to get it out from underneath the car

3. I also have a Scimitar and on that I took off the gearbox and left the bell housing in situ. In that case I replaced the bolts that connect gearbox to bellhousing with some threaded rod, then I was able to simply slide it backward until clear of the clutch. Then all I had to do was strap it to a trolley jack, removed the threaded rods and lower it down, and pull it clear. If that is an option for you it would be much easier IMO.

If I had my time again, I would take off the bonnet and remove the engine gearbox together. On a M series it lends it self to that because of the room to work sans bonnet. A lot less crawling around on the ground with very heavy things requiring lifting and trying to squish you as well as a chance to clean around the engine bay and apply heat proofing etc.

Dollyman1850

6,130 posts

208 months

Wednesday 23rd September
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i used to be young and daft and skint.. Those were the days 25 - 30 years ago when I used to work on my back on a drive Under cars... These days I either take longer and pull engines out or if I am contemplating seperating engines and boxes I do it on a 2 post lift..

Can it be pulled off in situ.. yes.. However it is extremely heavy to put back easily.. If you are going to do it..

1. Wedge the engine up so it cannot drop of the 2 front mounts.
2. consider making a support for your trolley jack to ensure the box is lifted square...
3. have 2 younger stupid TVR enthusiasts to hand to help lift it back into place.. a type 5 with `Cast Iron bell housing must be a contender for the heaviest car gearbox assembly ever made!!

N.

Gee Boo

Original Poster:

76 posts

145 months

Thursday 24th September
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Some very helpful advice and some good points to look out for,thanks. Ifeel I’m up for this and there’s no rush so will get seals and that rubber gearbox bush on order and then get the kettle on !!

V6 Pushfit

15,717 posts

68 months

Thursday 24th September
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Stigproducts said:
I also have a Scimitar and on that I took off the gearbox and left the bell housing in situ. In that case I replaced the bolts that connect gearbox to bellhousing with some threaded rod, then I was able to simply slide it backward until clear of the clutch. Then all I had to do was strap it to a trolley jack, removed the threaded rods and lower it down, and pull it clear. If that is an option for you it would be much easier IMO.
What did you do about the release bearing - it would be flapping about a bit and almost impossible to ‘harpoon’ with the input shaft ?

My money is on engine removal as it’s not that difficult and for the extra couple of hours worth it to save the aggro !

ATE399J

715 posts

195 months

Friday 25th September
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My vote goes with take engine and box out together. You’ll get it out but putting it back is altogether a different challenge.
Just had to do this on my Vixen and even on that it was worthwhile pulling the lot together.
If you have a lift and all the gear it’s a different story...

However, as already said, if it’s leaking from the rear there’s no need to remove it as seal can be replaced with ‘box in-situ.

Edited by ATE399J on Friday 25th September 17:22

SlimJim16v

2,977 posts

101 months

Friday 25th September
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It helps to have someone inside the car, with a rope going through the gearstick hole and around the back of the gearbox, especially when refitting.

It was a long time ago, but I'm sure I put the bell housing on first, then the box.

You also can't beat an old input shaft to align the clutch. Anything else is hit and miss.