80 series Land Cruiser

Submitted: Thursday, Apr 24, 2003 at 11:40
ThreadID: 4549 Views:3873 Replies:6 FollowUps:6
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Hi
I have just bought a 1991 80 series GLX Landcruiser standard Diesal 4.2 (287,000km) in overall excellent condition. It got a very good NRMA report. Only concern from NRMA guy, "Notchy 2nd and 3rd gear". It was reccomended that this was not an immediate thing to worry about. I have since driven the car on a Sydney to Noosa road trip, no probs......but, if you are approaching or engaging a long hill or are slowed down on a hill and need to do a quick change down from 3rd to 2nd this can really grate, sometimes very hard to slot it into 2nd. Also 1st to 2nd can be "sticky" if not timed properly.
For a long trip, off-road included, is this a worry or will I be ok to leave it?
Thanks
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Reply By: charlie - Thursday, Apr 24, 2003 at 11:48

Thursday, Apr 24, 2003 at 11:48
Zoobs I have a similar GXL turbo diesel and the gear box can be a little rough from first to second when it is cold. People have said that to help this it is a good idea to use a really good synth oil. Do a search on the subject and you should find something on it. Mine has just done 200k so I might have same probs further down the road. Good luck.

Charlie
AnswerID: 18279

Reply By: rads - Thursday, Apr 24, 2003 at 11:50

Thursday, Apr 24, 2003 at 11:50
Hi Zoobs
Had a similar car with similar km's with the same problem. Lived with it for a long time and never had any dramas. Mine seemed to be worse when car was cold. Father in law has same motor but with turbo, also has same problem. Apparently very common.
AnswerID: 18280

Reply By: Michael - Thursday, Apr 24, 2003 at 13:47

Thursday, Apr 24, 2003 at 13:47
O00HHHHHH what a feeling!!!!!!!!!!!
AnswerID: 18290

Reply By: Gordon - Thursday, Apr 24, 2003 at 14:10

Thursday, Apr 24, 2003 at 14:10
Zoobs
Your 2nd gear synchromesh is worn. Learn how to double de-clutch when changing down from 3rd to 2nd. This will stop the grating if you get it just right and at least minimise it otherwise. With practice you can get pretty good. Truckies use this method alot because many truck gearboxes have no synchro.

Changing up from 1st to 2nd should be OK once you get the timing right.

Worn synchro rings on 2nd gear is common on all old gearboxes. It's the gear that gets a hard time.

When changing down, I double de-clutch all the time even thought my synchro is still OK. It is kind on the whole drive train. Ever experienced the braking effect when you change down with no throttle? That puts a big load on the drive train particularly if you drop the clutch and it's even worse on a diesel (high compression).

I have an 80 Series TD. As a rough guide, I find that leaving my foot at the same place on the accelerator will be pretty close the the right revs when you select the next lower gear. So:

1. Declutch
2. Select neutral
3. Engage (momentarily) and de-clutch again
4. (Quickly) Select the lower gear
5. Engage clutch
6. Leave throttle position unchanged throughout.

You are tring to match the speed of two shafts in the gearbox. The speed of one of the shafts is dependant on your road speed. You control the speed of the gearbox input shaft using the engine but have to de-clutch again to get the gears to mesh.

The longer you wait between steps 3 and 4 the more chance of grating because the gearbox input shaft will eventually stop spinning altogether.

Hope this makes sense. Regards, Gordon
AnswerID: 18291

Follow Up By: Member - Cruiser1 - Thursday, Apr 24, 2003 at 15:16

Thursday, Apr 24, 2003 at 15:16
If you use double-clutching for down-shifting, it actually pays to give the throttle a quick blip just before engaging the lower gear. It helps to equalise the speed of the spinning parts.

Double-clutching is good practice in any older 4bee where the box might be a bit worn, especially just after start up in the morning.

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FollowupID: 11470

Follow Up By: Gordon - Thursday, Apr 24, 2003 at 15:39

Thursday, Apr 24, 2003 at 15:39
Cruiser1
Perhaps I didn't expain my method very well.

The problem with the "blip" method is that it can be difficult to judge the revs.

My method removes the guess work. I leave my foot on the accelerator at the same throttle position as I was using for the higher gear. When I de-clutch the first time the revs will naturally increase as the load is taken off the engine. I find that the revs increase to a point that is very close to the revs required in the lower gear.

This method works best in the situation where the thottle setting in the higher gear is maintaining the vehicle at constant speed. If the vehicle is labouring up hill then you will need to back off slightly. If coasting downhill then more throttle will be required.
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FollowupID: 11471

Follow Up By: Member - Cruiser1 - Thursday, Apr 24, 2003 at 15:52

Thursday, Apr 24, 2003 at 15:52
Yep, makes perfect sense. Must admit I've never tried that as I was brought up with the blip method.
As you say in your earlier post, timing is the key. Once you get the timing right, you can work all the way up or down the gears without even touching the clutch - a great standby if you ever blow a clutch. (Had to do this on a couple of occasions - always got me home...)
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FollowupID: 11472

Follow Up By: raybates - Thursday, Apr 24, 2003 at 18:07

Thursday, Apr 24, 2003 at 18:07
I remember many years ago when I was learning to drive (50yrs ago) I learned on a Bedford truck that had a crash gearbox that required double de clutch an with very carefull handling it is possible to change gear by gently VERY GENTLY rubbing the faces of the gears together till it was possible to engage the gear quietly. This method is OK for changing up and changing down if you have plenty of time. I usually use the blip method when changing down.
My driving instructor used to say that a clutch was a luxury item and that everyone should learn to drive without one. Towards the end of my lessons, he would only let me use the clutch for stopping and starting and if I was to grate the gears I would get a rap across the knuckles
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FollowupID: 11477

Follow Up By: Zoobs - Thursday, Apr 24, 2003 at 23:39

Thursday, Apr 24, 2003 at 23:39
Thanks to all for the detailed info. Much appreciated. Will get into a bit of double de clutching and try the good quality oil. Seems like there is no need to repair or replace at this stage. Thanks again.
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FollowupID: 11490

Reply By: Dozer - Friday, Apr 25, 2003 at 19:19

Friday, Apr 25, 2003 at 19:19
Hi Cruisers
The oil makes a big difference, and on the 80 series list (lcool.org) the general cons is that Castrol vmx-m gives the best outcome.
All 80 series 5 speeds were effected, later ones not as bad as earlier 90-92. Winter coming wont help things, so lash out and get that smile happening.
AnswerID: 18355

Reply By: colin - Monday, Apr 28, 2003 at 21:47

Monday, Apr 28, 2003 at 21:47
double de clutching on a syncro gear box is a no no this method is only used on crash boxes and road rangers syncros are designed to be used with the clutch fully in but you are right about getting the revs right with your change.using this method on syncro boxes in the transport industry will get you the sack. Col
AnswerID: 18635

Follow Up By: colin - Monday, Apr 28, 2003 at 21:53

Monday, Apr 28, 2003 at 21:53
sorry forgot to say getting your oil right in the box is the first priority, different oil for different vehicle, i have 92 4.2 diesal patrol and run penrite oil in all running gear at the advice of a running gear specialist done 260,000 ks and still good as new, smoooooth as but thats a NISSAN for you .COL
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FollowupID: 11631

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