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Gearbox knackered??

Posted: 21 Jan 2009, 17:54
by Reco
Real nasty vibration in first gear, less when pulling away in 2nd or G but still there.
But is perfectly smooth when in reverse.

Thought was cvj which was knackered but now fixed still have nasty vibration.

Checked front diff and oil like new :D

Checked and drained gbox: oil = new-ish when settled but grey-ish and a bit foamy (?) and plug looks like little black palm tree with fine shards and grey paste although no teeth or big chunks :roll:

I'd really appretiate an informed opinion......any ideas anybody ?

It could be something simple and cheap .......but its the gearbox isit...... :|

Seem to remember reading similar thread recently.

Re: Gearbox knackered??

Posted: 21 Jan 2009, 18:45
by Aidan
bad first gear is likely to be worn pinion bearing (1st is next to the pbearing and the biggest gear on the shafts (so that underload the shafts are being pushed apart), R and G gear are at the front of the box and are indirectly driven via the intermediate reduction gears hence less load on the shafts;
it's possibly the input bearing too, which is above the pinion bearing, these are quite small and have a hard life and suffer especially with torquey diesel especially upgraded engines; but even where these have failed the first gear seems to stay fairly quiet, though the mainshaft is quietly trashing itself against the bearing shell.
the swarf on the plug looks fine for fairly high mileage with no oil change, but if that's recent oil then it's high wear accelerating
imho

Re: Gearbox knackered??

Posted: 21 Jan 2009, 18:59
by Reco
Hi Aidan -thanks! was hoping for expert opinion.

Reverse is perfectly smooth - which made me realise how bad 1st was...like its resisting going forward.

Had truck nearly a year but was Russels @ syncronutz so reckon he would have renewed oil (judging by front diff oil being so clean) so could be wearing quite fast.
Yes is upgraded diesel engine.

So best bet is what -get box out and send to you for overhaul before things get worse?

(what does imho mean?)

Re: Gearbox knackered??

Posted: 21 Jan 2009, 20:14
by Russel
If this is my old blue single cab then the gear oil was not changed while i owned the vehicle.
The front diff oil was changed when i striped it to repair the diff lock and speedo drive.
Russel

Re: Gearbox knackered??

Posted: 21 Jan 2009, 21:54
by Aidan
imho
in my humble opinion
text shorthand sorry, sometimes they still slip in even when full keyboard and time are not a problem :D

Re: Gearbox knackered??

Posted: 21 Jan 2009, 22:21
by Reco
Hi Russel -yes your old blue single cab.
Great truck by the way....chuffed to bits with it and its got me and equipment where ever I've needed to get to!

So things looking up if oil not changed for a while / ever = oil condition not too bad at 162k-ish miles.
As I said no teeth or chunks - and changes fine, smooth when running in higher gears, no whining or poping out and perfect in reverse.

So Aidan - I know from forum you rebuild boxes but not sure if its something you do full time?
These bearings etc... something you can get hold of and could do if not too busy?

Some idea of cost and proceedure? time frame? would be useful to RKilshawEco@aol.com if you like

Unless someone has box for sale its got to be done -just pleased not too busy myself at the mo.

Re: Gearbox knackered??

Posted: 26 Jan 2009, 17:42
by Reco
Took off prop today and vibration gone!! :) :?
I know should have taken off earlier but had convinced meself of worst scenario - and still not 100% convinced!

Uj joint to front was dry and bit stiff, with slight 'notch' feel at extreme point of movement. Wd40'd it and can now feel slight play in it -not that smooth flowing of the other u joints (camper prop off as well now for comparism).

?? Unless taking prop off has reduced stress on gbox??
but seemed ok even under load -up very steep hill and accelerating hard away which would have shook my fillings out before.

Thought about swapping props but one from petrol camper looks a gnats todger longer than one from diesel truck...and both a 'perfect' fit on respective motors. plus dark now...anyone know?

If this is the problem then serious result!
I'm sure someone on here had prop refurb'd not so long back...anyone with a contact?

Cheers,

5/2/09 E D I T.
Well thanks anyway.
Just for completness of this thread: sent prop to GKN at Leek (top people!) who put 2 new ujs on and balanced. Now refitted, changed gearbox oil and all good!
Typically the one day a year when we get good snow the prop was off!!
Nearly couldn't get up steep hill back into village but 'G' and rear difflock saved the day!