5th gear crunch

[Dudi]

Evening,

Hopefully someone can help with an issue we're having with our track MR2.

It's a 2ZZ swapped car with a 6 speed box and ever since it was bought there's been a crunch into 5th gear. The weird thing is it doesn't happen every time but most times. It doesn't happen when the engine is off.

Also the car has a real issue coming out of reverse, no problem getting into reverse but when coming out the gear lever needs to be pushed towards second to make it pop out of reverse.

We spent time today installing solid shifter bushings and the linkage bearing which have made the changer smoother but the annoying 5th gear crunch is still there.

Any help much appreciated.

[Dudi]

Anybody?

Could it be clutch or gear linkage issue?

The reverse issue happens whether engine on or off. The fifth gear change is perfect with the engine off but crunch/grind when on.

[ChrisGB]

Tired synchro would be my guess.

[Essex2Visuvesi]

A change of the gearbox oil might help

I had a similar issue with my RX8 used to be difficult to engage 3rd
Oil was chaged to a high quality gear oil (Royal Purple if memory serves) and never had any more issues

[Dudi]

Synchro issue would be mechanical therefore it's either there all the time or not surely?

Would a synchro issue be present when the engine is off? (The fifth gear change is perfect when the engine is off.)

I'm wondering if it's something like clutch drag or gearbox mounts/linkage affecting the alignment. Can't help but think the fifth and reverse issues are linked as well.

[jonbill]

The syncro synchronises the speed of two spinning shafts in a gearbox in a running engine. If the engine isn't running the shafts aren't spinning.

A worn syncro may or may not crunch depending on the relative speeds of the two shafts when you shift and how fast you try to shift.

[jonbill]

And yes, quite possible the reverse & 5th gear issues are related. I don't know this gearbox in detail, but on others 5th and rev are often on same shaft.
If true of this box, might indicate bearing wear on that shaft rather than syncro wear.

[Dudi]

And yes, quite possible the reverse & 5th gear issues are related. I don't know this gearbox in detail, but on others 5th and rev are often on same shaft.
If true of this box, might indicate bearing wear on that shaft rather than syncro wear.

Thanks for the reply. As you might be able to tell I have no real knowledge of transmission internals.

The reverse issue is there all the time engine on or off. Would it be characteristic for a bearing issue to show with the engine off?

[jonbill]

Not sure really - I was thinking a collapsed bearing could put the shaft out of alignment and make it hard to engage.
But I'm guessing.
I'd try to rule out linkage problems before worrying about the insides.
See if you can see the movement of the gear change levers in thr engine bay while an assistant tries to put it in reverse and see if you can manually engage it properly.

[Dudi]

Not sure really - I was thinking a collapsed bearing could put the shaft out of alignment and make it hard to engage.
But I'm guessing.
I'd try to rule out linkage problems before worrying about the insides.
See if you can see the movement of the gear change levers in thr engine bay while an assistant tries to put it in reverse and see if you can manually engage it properly.

A Toyota specialist pretty much agreed with your diagnosis of bearing collapse or possibly shaft coming out of the bearing guide towards the end of the travel. In any case thank you.

Wouldn't happen to know a good gearbox specialist in Wales/Midlands/North West (Cheshire) area?

[jonbill]

I'm afraid I can't help with that - never had the need. But just replacing with a 2nd hand box might be the more xost effective option.

[Dudi]

I'm afraid I can't help with that - never had the need. But just replacing with a 2nd hand box might be the more xost effective option.

Fortunately I've got a spare near new C60 gearbox but will have to get the LSD swapped over. Hopefully I can find someone relatively local to get it sorted, opportunity to put a lightened flywheel and a new clutch as well.

[Dudi]

Anyone with prior knowledge of how many approximate labour hours it would cost for the following? I've had a quote of approximately £1000 just for the labour so seeing if that's the going rate or whether I'm having my pants pulled down.

Remove gearbox
Swap LSD from old to brand new gearbox
Install clutch and flywheel
Reinstall gearbox

[beavisrules]

Swapping the lsd is going to make them quote you a silly number.
Nobody like breaking apart a gear box, it can lead to a lot of unplanned extra work.

[Dudi]

Swapping the lsd is going to make them quote you a silly number.
Nobody like breaking apart a gear box, it can lead to a lot of unplanned extra work.

How do you mean unplanned extra work?

One box is brand new so no issues there. The other LSD is functioning well so it's just a case of removing the LSD, swap FD ring onto the LSD, set preload, assemble and add fluid. It doesn't matter if the old gearbox is more broken than the one synchro and bearing that we suspect because I don't have any further plans for it. I've been quoted 6 hours labour for the above.

The bit I'm questioning is 8 hours to remove and refit gearbox. Is that normal?

[beavisrules]

I'm referring to the fact gearbox has to be opened to change the LSD.
Garages don't like it because cleaning ,gaskets (or just sealant in this case) , leaks , more cleaning , don't really know what they're doing etc...
Most garages won't contemplate opening a gearbox and will send it away for anything like that.

If you found someone who's good with their toyotas then yes indeed it's technically easy.

8 hours for the swap sounds pretty good to me. and you do have to pay good money for good technicians unfortunately  s:) s:) .

[jonbill]

Yes I think that's right - if the company has to cover a warranty and make a profit on something they don't do everyday, then I think £1000 is reasonable.

[Dudi]

I understand what you're saying and I have had gearbox upgrades, final drive changes etc on other cars but considering the box I hope to have installed is brand spanking new the risk of finding any nasty surprises is pretty much zero.

I wish it was 8 hours, that's just for taking off the box and reinstalling it. Swapping the LSD is another 6 hours so 14 hours all together.

Is 8 hours labour the going rate for taking the box off and reinstalling it on an MR2 guys and girls?

This is with an MR2/Toyota specialist.

[JoeCool]

A gearbox specialist place did my LSD swap for about £200 whilst the transaxle was out of the car. It's not as bad as splitting the whole box, the final drive is in it's own segment on these transmissions, so you can safely work on the diff without risking scattering gearbox internals all over the shop.
'Personally, I''d be looking to take it to someone like Cabbydave (if he offers such services) or Headcase (Wrong end of the country) or Bonsai Garage (Weston Super Mare) to get it looked at. They know these swaps well and should be able to sort the issues.

To me it sounds like your selector shaft could have been put together wrong or else the linkage positioning, giving you difficulty in the extreme left/right plane. But I haven't done the work myself and wouldn't know what I was looking at.

[Tedtiler]

Reverse issue is the little bush in the far side of the gearbox where  the celica linkage used to enter. The mr2 selector shaft falls out of it when you select reverse.

So whatever you have used to block that hole with, open it again and push the little bush the selector slides on approx 10mm further into the box.

This can be done on the car

[Tedtiler]

The lsd can be put in just by opening  the bellhousing if you know what  your doing.