Fly Wheels

[the godfather]

Hey All,
Well end of last year i did some damage to my little Patrol.
Usual stupidity involved. I was 100km out of Eucla, bogged up to the axles with the camper in tow, going up a dune.
I couldn't reverse as the camper track is wider than the Patty and she kept jack knifing.
So rather than unhitch and snatch the camper out I gave her a foot full.

Crack, bank, crack………sh@#$%@ (insert appropriate bad language you would use here)
Anyhow, I eventually calmed down and managed to get back down. I couldn't see any damage and still had to get back to Perth. So I took a long run up and hit the dune fast and hard. I made it out.
I know I had damaged something, either the box (manual), clutch, or flywheel. She rattled all the way home.

Long story short. She stopped. Now the engine is out and the guts of the flywheel (dual mass I think) is broken.
Question I have: does anyone have a part diagram for the flywheel on a GU 2001.
I know I can get a new flywheel. But I want to look at a diagram to see how and why this has happened.
Cheers
The Godfather.

[garett]

the dual fly wheels are regarded as non repairable, its two pieces with a spring absorbing shock ( like a clutch plate ). (if i remember right the spring weakens till it breaks then it hits the stoppers and rattles) I hear of a few of these failing. and some cars you can fit a normal flywheel but it will shake every time you try to take off.

[Rock Trol]

The DMF is a tuned device, meaning it is designed to handle a certain amount of power and load from the factory. If they build them too strong it wont absorb the vibrations from the engine and would be similar to a single mass flywheel. If yours is a 2001 and you have been towing off road then it has really done well to hold together. It is a compromised device in that it sacrifices strength for drivability and smoothness. They can give up the ghost at any time without warning. A mate and I where in the high country a couple of years ago and his DMF failed at the bottom of the stairway to Lake Cobbler. It leaked oil from the buffers all over the clutch and there was no drive. I had to tow him all the way up and over the mountain as it was too narrow to turn him around.

Personally I prefer a single mass flywheel but it does change the way the vehicle drives. There is more gearbox chatter (vibration when idling) and you have to change down gears sooner or car starts to vibrate. As for prolonging the life of a DMF, just be gentle with them. If you have had the car since new and its the first time you have had problems then you are probably driving it the correct way. I think it was probably just wearing out and that last hill with camper was the straw that broke the DMF's back.

[the godfather]

Wow, thanks for the information. I guess I have been lucky then. 320,000 km with out having it break.
It has worked extremely hard and done some serious off road towing. I am generally nice to her because I believe in treating my vehicle well, so when I really need it to work hard it still can.
Either way, looks like I will put a single mass flywheel in.
I have a trip planned to cross the mighty Simpson Desert later this year. The less to go wrong the better.
That said, I am not towing the camper across. Will just be a tent this time.

[Rock Trol]

That's a good run by any standard. My mates gave out at around 140,000 km's. I had mine swapped out at 112,000 km when the engine was removed to fix some issues under warranty. It was ex-Telstra and the mechanics told me the clutch was 70% worn and I should take the opportunity to change it as it would only be the cost of parts. They steered me towards a single mass unit as they would only change the clutch and flywheel together for a DMF unit. Saved me around $700 and the single mass flywheel is reusable and can be machined. They were a Mazda dealership and said it was very common on the BT50's that towed trailers (tradies) so they just swap the whole lot out and never have any coming back.

If you have driven older diesels with single mass flywheels it will feel the same. Not that bad and you get used to it. You just need to downshift sooner. The upside is that the pedal feel is much better and you really know when the clutch is starting to take up. Some people hate them and I have read on forums that they have soon swapped back to a DMF and swallowed the cost of 2 clutch/flywheel changes. This is pretty rare and all the people I know who have installed single mass flywheels would not go back to DMF (3 people in my 4WD club as well as me).

[Bigcol]

WTF..............

honest mechanic's - well I never..................

[Rock Trol]

I was like a stunned mullet. The car had oil leaks from several places and the dealership decided to do the job properly and remove the engine to redo the gaskets.
Even better, it hasn't leaked since (3 years and 30,000 km) :smiley_thumbs_up:

[the godfather]

Clutch conversion kit sorted. $1207.00 inc GST. Includes everything I need apparently.

[Scarface]

hi Fella's, what if i just change the clutch and leave the old DMF ? has anyone done this and was there any dramas?

[lucus30]

well you can't machine DMF. I'm pretty sure you would just wreck your new clutch quickly

[4bye4]

hi Fella's, what if i just change the clutch and leave the old DMF ? has anyone done this and was there any dramas?

Yea did it on Merc Vito work van. Sounds like a tin full of nuts and bolts when trying to reverse. Its warped and grabs and slips all over the place. IMO, get rid of the damm thisng and put a SMF in with the new clutch. DMF? mutter mutter mutter.

[Rock Trol]

If the flywheel is worn and you put just a new clutch in, then it might not last very long. Then you have to do the job twice.
That is why workshops refuse to machine them and insist on a new clutch and flywheel. Too much of a risk that something will go wrong soon after and the customer will return and blame the mechanic for bad workmanship.

[mudski]

Your crazy if you do scarface. Firstly, the clutch has instantly lost its warranty, the workshop, if a workshop would do it, won't warrant it. The box is out. Its a big job to remove the box. Why wouldn't you change the flywheel.

[the godfather]

Well, I know it has been a long time. But the engine is back in...yay.!
New single mass flywheel and clutch.
Removed and cleaned the intake manifold and associated pipes etc.
NADS done. Well they where done ages ago apart from the Exhaust Temp gauge fitting.
Broke my turbo vacuum reservoir in the process. $98.00 ex-Japan for that bit.
Some new heat shielding around here and there ($145.00 for 600mm x 300mm sheet).
Several broken bolts under the chassis I need to drill out some time.
The outcome is that the Single mass makes it feel like an early model HZ75 Land Cruiser at low revs. Smooth after about 1800rpm. No big issue.
Need to make note that the thrust bearing is different to the one supplied if you have stepped up your gearbox main-shaft and 5th gear, as I have. Again no real issue.
I changed out as many gaskets and seals as I could while I had the engine out.
Now she has heaps more power, and apart from being marginally louder she is a far better bus.
I took her out today for some serious rock climbing as a test. Both the missus and I came home smiling and planning for the Simo trip.

[threedogs]

I was like a stunned mullet. The car had oil leaks from several places and the dealership decided to do the job properly and remove the engine to redo the gaskets.
Even better, it hasn't leaked since (3 years and 30,000 km) :smiley_thumbs_up:

What an honest mechanic that does great work.
Well hit me with your rythm stick,, rare find

[Rock Trol]

Good to hear that you are happy with flywheel conversion Godfather. It's a little rougher but knowing its a lot tougher than before should make up for it.
Also, if you modify the engine for more power in the future you won't have to worry about the flywheel giving way.