I keep breaking CV's on my 80 even when driving quietly

Submitted: Friday, Aug 06, 2010 at 14:38
ThreadID: 80552 Views:5041 Replies:7 FollowUps:11
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Hi everyone

Got a 94 80 series auto turbo diesel.

It's the model that's got a viscous coupling in high range and a centre diff lock in low range, but there's no centre diff lock button on the dash to engage it in high range. ABS if it matters.

I've broken 3 CV's in 9 months 15000 km with 33 inch mud tyres and front and rear diff locks. The first time, I was driving quietly in light snow nearly dozing off it was so smooth and quiet and it broke.

I make my aim to get up things with my hands and my head before I use my wallet or my right foot and rarely use momentum.

The last one I broke was a week ago, going up a small rutted section on a hill, got caught on the rear diff, pulled out the winch and I was helping the winch (about 1800 rpm) and rocking the wheels left to right (not rocking them too far) and all of the sudden, bang, broke a CV. Had the diff locks on.

I broke it just helping the winch. This CV was only 15000 km old to

Some claim that I shouldn't have been rocking the wheels, but when they pulled it apart, the inside of the CV was broken, not the outside, and apparently that means that steering had nothing to do with it, the trouble is when it broke on the inside, it stuffed my axle to.

My mechanic claims that 80 series CV's are technically just as strong as GU CV's, but the 80 is a full time 4wd, so you get 10 times the wear and tear on the CV's, Nissan's cheated and made theirs a part time 4wd.

I live in an extremely wet area and have got all round mud tyres for a daily commuter, so a full time 4wd with a viscous coupling is very handy.

A friend in my area had a part time 80 with 38 Super Swampers and drove up cliffs and his CV's never missed a beat. His argument to it is if I made it a part time 4wd, the money I'd save on fuel and wear and tear on the car, I could always have new tyres on and there's my full time 4wd on wet roads and a beast off road and a strong car.

Is there any fancy way that I can make it similar to the Pajero, full time when you want it and part time when you want it? It wouldn't bother me to have to jump out and lock in / disengage hubs. If I could do that, it would be the best of all worlds.

Maybe any tricks on making them stronger / heavy duty ones, or would that mean I break my diffs and axles?

Thanks everyone
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Reply By: Member - Tour Boy ( Bundy QLD) - Friday, Aug 06, 2010 at 15:36

Friday, Aug 06, 2010 at 15:36
Hi, leave it as it is and stop using chinese junk CV's, they break as often as you describe.
Cheers
Dave
Cheers,
Dave
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AnswerID: 426361

Follow Up By: Rockape - Friday, Aug 06, 2010 at 17:03

Friday, Aug 06, 2010 at 17:03
Agree with Tour Boy,

Use genuine Tojo ones.
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FollowupID: 696939

Follow Up By: kingkennas - Friday, Aug 06, 2010 at 17:16

Friday, Aug 06, 2010 at 17:16
Sorry should have mentioned which ones I use.

I use Toyota genuine Japanese ones, the only way to go further are heavy duty ones meant for comps, don't know much about them though and putting them on may mean I break my diffs instead.

If anyone knows much about them, fire away.
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FollowupID: 696940

Reply By: dieseltojo - Friday, Aug 06, 2010 at 17:07

Friday, Aug 06, 2010 at 17:07
Hi kingkennas,

Join Lcool and post your question there,or do a search.

http://www.lcool.org/forum/index.php?sid=f578930720318e5954bec3e8f96151d3
AnswerID: 426364

Reply By: Cruiser 2091 - Friday, Aug 06, 2010 at 18:38

Friday, Aug 06, 2010 at 18:38
there are adjustable stops on the knuckle joint to prevent the wheels from turning at too greater angle. I wonder if these have been screwed in too far at some point because turning a CV joint past it.s maximum recommended angle puts increased strain on the joint. Normally CV's will last for hundreds of thousands of Ks on an 80 series.
AnswerID: 426370

Reply By: brissle - Saturday, Aug 07, 2010 at 20:05

Saturday, Aug 07, 2010 at 20:05
you can get a part time kit check out
http://www.4wdsystems.com.au/index.php?id=30
AnswerID: 426533

Reply By: gbc - Monday, Aug 09, 2010 at 05:58

Monday, Aug 09, 2010 at 05:58
The last one I broke was a week ago, going up a small rutted section on a hill, got caught on the rear diff, pulled out the winch and I was helping the winch (about 1800 rpm) and rocking the wheels left to right (not rocking them too far) and all of the sudden, bang, broke a CV. Had the diff locks on.

Perfect way to bust one.

It's your driving style that's breaking them.

Leave it unlocked if you're going to 'rock' it at 1800 rpm - or better still get out and winch it properly.
AnswerID: 426707

Reply By: gbc - Monday, Aug 09, 2010 at 06:02

Monday, Aug 09, 2010 at 06:02
The last one I broke was a week ago, going up a small rutted section on a hill, got caught on the rear diff, pulled out the winch and I was helping the winch (about 1800 rpm) and rocking the wheels left to right (not rocking them too far) and all of the sudden, bang, broke a CV. Had the diff locks on.

Perfect way to bust one.

It's your driving style that's breaking them.

Leave it unlocked if you're going to 'rock' it at 1800 rpm - or better still get out and winch it properly.

"A small rutted section on a hill" - that a twin locked '80 on 33's couldn't drive? It's either not as described or you can't steer.
AnswerID: 426708

Follow Up By: kingkennas - Monday, Aug 09, 2010 at 09:00

Monday, Aug 09, 2010 at 09:00
I mean it was a short rutted section, deep ruts though and very very greasy

I've done training from basic through to advanced recovery with senior instructors and they train you to help the winch especially when you've got an auto and when you're trying to keep the car moving, rock the wheels left to right.

I've seen thousands of people rock the wheels and never break anything and with me, it's a case of using my hands and head and driving obstacles quietly instead of using my right foot to get up, so it's probably easier on the car at the end of the day.

But yea, some say to never rock the wheels, some say to not help the winch, some say help the winch and rock the wheels, but don't have to front diff lock engaged, I don't know who to believe, so at the end of the day, the best I can do is listen to the four wheel drive specialists that I use and listen to senior 4wd trainers.

The way a couple of them look at it, if my car's not capable of me helping the winch and rocking the wheels slightly for the sidewall to dig in the keep the car moving and not need as much throttle and reduce the load on the winch, then my car is so weak that I shouldn't be taking it off road.

The way another mechanic looks at it, when I was helping the winch, I was reducing load on the winch and halving the chance of breaking it and breaking a winch is just as bad a breaking a CV, and I was reducing load on the batteries and alternator with I suppose is handy.
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FollowupID: 697297

Reply By: gbc - Monday, Aug 09, 2010 at 10:14

Monday, Aug 09, 2010 at 10:14
I don't want to get up your nose, but I have a habit of writing differently to the way I speak - I am just trying to help.
First - I've done a bit of training myself, and racing - actually quite a bit in a challenge class 80 series. When racing it is common place to try to gain traction whilst winching - it's obviously a faster way to get up the hill. These are generally modified vehicles.
A T.D. auto 80 in low range even gently trying to rotate both front wheels when they are jammed on a winch - especially when the driver is turning the wheel - is going to pop c.v.'s. There are no ifs or buts about this - add a locker and it's twice as likely. You can of course purchase heat treated or cro-mo c.v.'s and they will last longer, but if you don't modify your driving and recovery methods the damage will get worse. Just trying to help you before you get that far mate.
Second - don't let anyone tell you an '80 series c.v. is as strong as a patrol c.v. - the steel might be, but the design isn't. Try youtube - this has been proven on a calibrated c.v. snapper and the results have been video'd for all to see - and they broke longfields and all other brands of c.v.'s too. It was at the tuff truck comp a few years back. Patrols have their own set of issues - like cooling, and blowing up.
Third - A part time kit simply isn't going to make them last longer. It might prevent them from wearing out quicker, but wearing out a c.v. is just a dream for you at the moment. They are being destroyed because they are being subjected to too much torque is being applied to a longer lever (33's) and the c.v. fails before the vehicle moves forward from the obstacle on which it is stuck. Come to think of it, a part time kit with some cheap hubs might be right up your alley - heaps cheaper and quicker to change a hub than a c.v. - they don't call them axle fuse's for nothing......
Finally - don't try to help the winch - the dynamic load you apply to it when you fall backwards whilst trying to help will kill it faster than using it as it is designed. If it is struggling you'll need the snatch block. End of story - it's not a race. If you want to get up hills quick buy a custom 24v racing winch.



AnswerID: 426723

Follow Up By: kingkennas - Monday, Aug 09, 2010 at 10:53

Monday, Aug 09, 2010 at 10:53
I'll give your way a shot, you seem so dam sure, but all I can tell you is it's the opposite theory to experienced senior 4wd trainers and experienced 4wd specialist mechanics.
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FollowupID: 697309

Follow Up By: kingkennas - Monday, Aug 09, 2010 at 12:31

Monday, Aug 09, 2010 at 12:31
Forget about the one I just broke, look at the one where I was cruising along quietly in snow that a Subaru could do no dramas and it broke.

9 out of 10 people I've told about this believe that there's probably something wrong like a bent diff housing or a broken viscous coupling or something wrong with my genuine diff locks that take forever to turn on and off, something like that and my mechanic currently fixing it agrees and is going to look into it.

Even if the last one I broke is my fault, there's still very likely to be something wrong with my car.
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FollowupID: 697319

Follow Up By: Alloy c/t - Monday, Aug 09, 2010 at 14:43

Monday, Aug 09, 2010 at 14:43
"forget about the one I just broke" If a scooby doo could do it easy then WHY were you in low range with centre diff locked and front and rear diffs locked ? time you learnt how and WHEN to use the traction your vehicle is capable of properly.
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FollowupID: 697334

Follow Up By: kingkennas - Monday, Aug 09, 2010 at 16:04

Monday, Aug 09, 2010 at 16:04
Because I was stuck and was winching and wasn't working the car mighty hard while actually in the winching process when it broke.

There's a difference between working the car hard to get up and winching and driving the car a little to help the winch.

It's possible to be on an extreme track (this was medium to hard) and be winching and working the car only a little bit while winching a hard track.
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FollowupID: 697351

Follow Up By: gbc - Tuesday, Aug 10, 2010 at 07:17

Tuesday, Aug 10, 2010 at 07:17
You're missing a very important engineering point - the torque that breaks your car comes from an external source, not an internal.
The winch is dragging your car which is unable to drive. If the driveline is engaged, this process will exert more force on the c.v.'s than driving can. Especially when you make a couple of inches and fall back - again this will create a dynamic load for a millisecond which will snap drivelines. Hence leave it out of gear, get out and winch.
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FollowupID: 697429

Follow Up By: kingkennas - Tuesday, Aug 10, 2010 at 09:28

Tuesday, Aug 10, 2010 at 09:28
I'd never leave it out of gear and driver trainers are very strict to have it in gear whether it's a manual or an auto because if something goes wrong like the cable breaks, the last thing you want is for the car to be in neutral and if you've got a manual, you just stall the car immediately and secure it.

Every driver trainer out there says to never winch from outside the car, there must always be someone in the drivers seat of each vehicle and preferably get the passengers out especially is snatching because when snatch straps break they normally go directly forwards or backwards and you must try and have it hooked up on the middle or the passenger side of the car with no passengers in it.

If I did what you've suggested, if the cable broke or something like that, the car would go flying back down the hill and the damages would be 100 times worse than breaking a CV and it could kill someone as well and could destroy your mates cars behind you and it doesn't help matters when you're out in the bush and you've got one or maybe more destroyed cars.

I've watched heaps and heaps of theory nights for basic / proficiency training courses done by different driver trainers and a lot of them show a video of an FJ40 who didn't go through the stall stop process properly and his car went flying back down this rocky hill and he couldn't stop and the back of his car hit a tree and he broke the back of the seat and went flying back into the back door and had spinal injuries, if I had it out of gear, that could happen to me.

I've been watching training courses since I was born because my father was a senior instructor for the association training other trainers and working together with people like Mike Smith and I was watching training most weekends when I was a child, not just basic / proficiency, but all your others to like snow and sand and advanced recovery. Eventually I could spell them backwards so much that my clubs asked me to help with the courses when I was 16.

Your theory might be true that helping the winch can break your CV, but on the other hand, about 20 separate driver trainers I've watched through time tell you to help the winch especially with an auto and don't go on and off the cable and this is one advantage with an auto, it's easier to help the winch and that's one reason why more and more comp guys are switching to automatics.

Every driver trainer is sooooo strict to do what I was saying about be in the car with it in gear.
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FollowupID: 697436

Follow Up By: Alloy c/t - Tuesday, Aug 10, 2010 at 09:44

Tuesday, Aug 10, 2010 at 09:44
You still dont get that the actual problem is YOUR driving style , YOU dont NEED or WANT your F+R diff locks engaged when your under winch load , let the winch do the work , your snapping CV,s because of the ON/OFF/ON/OFF power . Jerk -jerk -jerk.
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FollowupID: 697437

Follow Up By: kingkennas - Tuesday, Aug 10, 2010 at 10:14

Tuesday, Aug 10, 2010 at 10:14
Like I said, I agree that what your saying is probably true, but it's still not what very experienced senior 4wd trainers tell you, I'm not saying you're wrong, I'm just saying it's different.

I've seen probably 1000 cases or people helping their winches and haven't broken anything, but I can see where your theory comes from and agree that you may break a CV by helping the winch.
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FollowupID: 697441

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