question Axle / transmission wind up !!!

[POPPY]

Hi,

 

 

I was driving my 1944 CMP LAAT home this afternoon from a bank holiday show in rather muddy water logged field. It had rained none stop all weekend.

 

 

I fired the old girl up and selected 4 wheel drive. I drove across the boggy fields no problem taking it real easy.

 

 

When I was out and clear from the mire and onto the hard Tarmac road , I tried to select 2 wheel drive for normal road use..... But the lever was really hard to select 2 wheel drive ..... I shunted forward slowly in first gear then tried again.... With a little less resistance I finally got her into 2 wheel drive and set off home.

 

 

As I got up to 20 mph the Cab started bouncing. I pulled over to check if I had a flat tire , but all tyres were fine....... I set off sgain and the bouncing had eased off this time when I got to 20 mph but I noticed that my engine was working harder than usual and it was taking longer to reach cruising speed (35-40mph) :confused

 

 

It felt like I was towing a trailer!........ I pulled over again to check if my hand break was released properly or if I had a sticking break drum on one of the wheels ?....... The hand break was free and the wheel hubs cool.

 

 

I then tried pushing my lorry on the flat road but I could feel more resistance than normal ..... I tried to select 4 wheel drive again as I suspected that the transmission was to blame.

 

 

The selector moved into 4 wheel drive but wanted to spring back hard into 2 wheel drive ..... After selecting 4 wheel drive I reversed back a couple of foot and forward a couple of foot.

 

 

I then set off again in 2 wheel drive . It still felt like I was under powered and towing somthing ? I continued on and after a mile or so there was a loud bang and the lorry felt like she hopped or skipped :eek:

 

 

Suddenly my power came back and I was up to crusing speed and all felt and sounded healthy again...... I got the lorry home safely.

 

 

Can anyone one kindly tell me if this was a bad case of Transmission Wind up? ..... Has that loud bang caused any damage ? ..... And what can I do different next time to avoid axle/transmission wind up ?

 

 

I really hope I haven't damaged the old girl !!!! I've only just got her back on her feet .

 

 

Kind regards,

 

 

Mark Towers

[Richard Farrant]

Mark,

As you observed, the box was under pressure from the axles and would not slip out of 4wd. What I normally do with my Bedford is ease it out before leaving the soft stuff, or failing that, run the wheels on one side on to a grass verge, or similar, this will take the pressure off the gears and allow it to slide out of 4wd.

[arcot1751]

You can also try reversing a bit before trying to select 2wd from 4. It has worked for me.

[N.O.S.]

Also steer from side to side, although reversing seems the best way. I often take my Bedford MJ out of 4wd just before the really hard ground, while the wheels will still slip a little - before it gets a chance to go tight.

[Tiffy_massive]

They used to tell us to bounce the vehicle of some curbs to get rid of the windup. Always worked, but probably not the best thing to do with some older vehicles.

[Tony B]

I have a standard practice , developed over many years, into 4 x 4 do the job . Stop on hard 6 foot backwards then into 4 x 2 . My first vehicle was a 1968 Austin Gipsy, that used to do it.

[Pete Ashby]

I've always used the backing up method, sometimes a couple of shunts forwards and backwards are required although running on the soft after shifting out is equally as good. Even the modern stuff can suffer from it, my L200 can be difficult to shift out of low 4x4 on occasion.

 

Pete

[RattlesnakeBob]

I'm sorry to be the one to say it but ....the loud 'bang' was (unless you were very lucky) something letting go to ease the torque ......probably a front axle half shaft ? ...... I say front because you said she continued after the bang 'nice and normal'?...

. so I presume you still had full drive to the back end ? I'm not familiar with your vehicle so ... don't know the construction of your transfer case but occasionally with Landrovers its the gubbins that engage the front axle in the transfer box that will have given out

'Wind up' is very common with selectable 4x4 and I've always tired a few things to unlock / unwind them ...

....pulling onto a grass verge with 2 of your wheels (either side it doesn't matter which) ...and giving her a bit of rev to spin those wheels will usually work .. or as someone else suggested .... slip her into 2 wheel drive whilst still on the muddy field and letting the back wheels spin a bit will also clear it out ...anything you can do to get a wheel to be able to spin will usually work basically ... vigorous turning of the steering wheel with one of the front wheels on something that it can spin on ...or as someone else also said... letting her bump over a few things such as kerbs as a last resort ....all you're trying to do is get a wheel to spin basically .... on a Bedford 4x4 I encountered we had to jack one wheel up and you wouldn't believe how it span all on it;s on accord to free itself ..... I use my 'modern' Mitsubishi a lot in 4x4 and it's no better on her ... I have to be really careful especially if I have engaged the rear diff lock whilst off road as although you can shift the lever you can rapidly tell she has not come out of 'full drive' ....

I do hope you haven't done too much damage but as I said , the first thing I would investigate is the front half shafts

Edited September 1, 2015 by RattlesnakeBob

[radiomike7]

^ IMHO you are being overly pessimistic, the bang and jolt was more likely the dog clutch finally disengaging and releasing the torque, rather like when a vehicle jumps out of gear. A simple check would be to run the vehicle up in 4wd while on stands and see what is turning. Don't forget most older vehicles with tandem drive axles on the rear had no inter axle diff and suffered from constant power sapping wind up as it is impossible to guarantee equal diameter tyres.

[POPPY]

Thank you all for your inputs ... And very helpful advice !!!😃👍

 

I will find some axle stands and carry out the nessesary checks and report back to this thread to let you all know how I get on

 

kind regards

 

Mark

[Topdog]

Good luck Mark. I hope it all works out ok without damage.

[travitara]

Hi,

I'm new to the forum and to the world of 4x4. My vehicle is actually a Suzuki Vitara (called sidekick in the US) ('96), with part-time 4WD. I'm asking here because there seem to be some very knowledgeable people in this forum

I was recently on a steep gravel slope and, having trouble getting up it, came to a full stop and engaged 4L. As I tried to climb, the vehicle slipped backward a bit (I should have used the handbrake...) and the front tires span, while the rear ones did not. I heard a loud "clunk" noise from the front of the vehicle. Since then (2h ago), there's a loud noise (as if someone were hitting the botton of the vehicle with a spanner) coming from the front whenever 4WD is engaged (this doesn't happen in 2WD). I've also noticed that the steering is tighter than before, particularly when turning right.

Could this be a sign of transmission wind-up? It clearly has to do with the front axle, as it only receives power when 4WD is engaged. Could jacking it up on one wheel relieve the tension? (and if so, how is this done? Do I leave the vehicle in gear, jack up one wheel, then put it in neutral and switch to 4WD? And if that doesn't work, try the other wheel?)

Or may the damage already be done?

If I had the means, I'd lift up the entire vehicle with 4WD engaged and see which wheels spin and which don't, but it's not the case...

Any advice?

Thanks in advance!

[Wendelspanswick]

My guess is you've snapped a front half shaft or the front transmission shaft, the test is to stick it on axle stands and see what turns in 4wd.

Edited January 23, 2018 by Wendelspanswick

[gordonb]

Or the front diff. Someone will know which goes first on a Vitara. As it is now noisy I'd go for a broken tooth in the diff.

 

Gordon

[travitara]

Hi and thanks for your replies!

This morning I tried it out again and noticed that if I leave it in neutral downhill, with 4WD engaged, it coasts down the hill slower, as if something were holding it back. I talked to my usual mechanic, who is accustomed to working with 4WDs, and he suspects that based on the symptoms above, including the one I just mentioned, it's probably the transfer case..

It would appear that getting a second hand transfer case might be cheaper than repairing it...

Could it be the chain? Just a tooth?

If I understand correctly, the front drive shafts are connected directly to the transfer case, so even when 4WD isn't engaged, steering might increase the risk of messing things up even more, so the vehicle should probably remain stationary until I can get it fixed.

I had no idea it was so delicate, I've only had the car for a couple of months...perhaps it was already damaged before I bought it

 

Edited January 23, 2018 by travitara

[hotel magnum]

I always went for the jacking of one wheel when trying to dis engage 4x4 if it did not release on its own, and as said the amount of torque stored is huge, so be a bit careful not to let your arm get dragged in between the tyre and road, 

[john1950]

Mack or Volvo power in the flat floor?

[hotel magnum]

Volvo eng and auto box, it had a bit of a bad time after I had to move to an MAN, (which I fell out of as they put the doors on wrong and could not get out of on the ferries as the trucks are so tight, yes the poor old magnum got hit from behind and pushed into the truck in front so both the trailer and cab had a bashing, then when it came back it was sliver in colour then jack knifed in Sweden so back to the menders again, when I visited the yard Christmas she was parked in the corner looking a bit sad and is up for sale, it was a good truck never let me down took it all over Europe loved it, the first one I had had the mack in same thing never missed a beat, I liked them and with the new trailer on I thought I was the bees knees no need for lights stainless or frilly curtains, miss it now though.

[john1950]

I was never a fan of Man s. That Volvo I shift is the market leader even after the years since its introduction the others have not caught up. Only thing I did not like was the gear selector was not iluminated, Working a lot of night shifts I missed it. It is funny though the Renault electricians have the engine mapping sorted better than Volvo. That flat floor cab on tramping must be great. When I drove a car transporter with a peak the only way to get dressed was lying down.

[john1950]

On 23/01/2018 at 12:25 PM, travitara said:

Hi and thanks for your replies!

This morning I tried it out again and noticed that if I leave it in neutral downhill, with 4WD engaged, it coasts down the hill slower, as if something were holding it back. I talked to my usual mechanic, who is accustomed to working with 4WDs, and he suspects that based on the symptoms above, including the one I just mentioned, it's probably the transfer case..

It would appear that getting a second hand transfer case might be cheaper than repairing it...

Could it be the chain? Just a tooth?

If I understand correctly, the front drive shafts are connected directly to the transfer case, so even when 4WD isn't engaged, steering might increase the risk of messing things up even more, so the vehicle should probably remain stationary until I can get it fixed.

I had no idea it was so delicate, I've only had the car for a couple of months...perhaps it was already damaged before I bought it

 

Jack up both wheels on the same axle then rotate one wheel the other one should turn or you will hear some noise.  

[Lauren Child]

Just a plus 1 for anyone else who finds themselves in the same sitation.  Jacking one wheel up and letting it spin the the tension out will prevent a nasty bang.  Then you can change back to 2wd.

[travitara]

17 hours ago, john1950 said:

Jack up both wheels on the same axle then rotate one wheel the other one should turn or you will hear some noise.  

Thanks!  My vehicle has open  (non-lockable) diffs...would that still work in my case?

[john1950]

Yes, If you put it in 4wd to stop the propshaft turning, turn one the other will go opposite way. This way you will be able to get a idea if the Sun and Star gears have been damaged. If you take it out of 4wd the Crown wheel and pinion will turn if there is a level plug in the diff case you can check the teeth as you turn it.   Have you drained any of the oils and looked for debris?

Edited March 11, 2018 by john1950
addition

[hotel magnum]

the later one with the higher roof and aircraft type locker across the back was ideal as we always double manned. which was also ideal as then tea was brewed all day, luncheon was made on the move, and we usually did 3 on 3 off driving much better to have a 3 hour break rather than a 45, even with the stopped meal in the middle of the day, always some one to talk to of an evening, and conversation over breakfast, a very civilised way to spend the day.

[john1950]

Gone Green with envy