LT230 front output shaft play

[Maverik]

Ok, all excited at having my truck (86 LR90 with Disco 200tdi) back on the road after re-build. Well having got out and driven it all seems ok, but from time to time you get an intermitted vibration and winning noise. Got under it last night and had a good shake of all the drivtrain, now props front and back bolted to a re-con transfer box... I know there is play on the rear axle pinion drive, but when checking the front i found play in the output shaft on my transfer box, really Mildly miffed as its done less than 100k!!! can it be such a simple solution as tightening that big nut on the drive flange? or is it a remove the transfer box jobby? The re-bulder of the box has been informed, I'm just waiting for a response if I ever get one...!

I was reading Marco's thread about re-building them, I have another 1.667 I might take a part and re-build... can you straight swap the input gear for a higher ratio one? e.g. 1.4 or 1.2?

cheers

Mav

[reb78]

Depends on how bad the play is, but it could be the output bearing - that can be changed in situ - check out the tech archive for a 'how to'

To change the ratios, it is the intermediate gears you alter, not the input gear, but as far as i know, you can change them between casings.

[Retroanaconda]

I thought a small amount of play was normal, because it's a roller bearing and not a taper one?

Or is that something else?

[Maverik]

I've just been looking at verious posts and the workshop manuals and parts too... Quite suprised its not a taper set up to be honest, I can see that there might be some play axially but not from side to side... assuming it was a new bearing used and that's "ok" then the only other reason is wear of the bearing seat on either the main drive shaft of the actual housing... The guy that re-built the box rang me promptly after the email I sent him this morning, so at least he's semi concerned.

Looks easy enough to change the bearing/shaft etc. in situe, but doesn't look so easy to do the front housing in situe...

[ashtrans]

Ok, all excited at having my truck (86 LR90 with Disco 200tdi) back on the road after re-build. Well having got out and driven it all seems ok, but from time to time you get an intermitted vibration and winning noise. Got under it last night and had a good shake of all the drivtrain, now props front and back bolted to a re-con transfer box... I know there is play on the rear axle pinion drive, but when checking the front i found play in the output shaft on my transfer box, really Mildly miffed as its done less than 100k!!! can it be such a simple solution as tightening that big nut on the drive flange? or is it a remove the transfer box jobby? The re-bulder of the box has been informed, I'm just waiting for a response if I ever get one...!

I was reading Marco's thread about re-building them, I have another 1.667 I might take a part and re-build... can you straight swap the input gear for a higher ratio one? e.g. 1.4 or 1.2?

cheers

Mav

I am not sure if we supplied this or not but I will try to help anyway,

this front bearing often feels loose as it's a roller bearing not a taper roller bearing, what you can feel is more 'rock' than 'lift' and in my experience it feels way worse than it is, ie we regularly have customers phone saying they can move it 3mm up and down, then when it comes in and you put a clock on it you struggle to get it to move 0.2mm which is normal, as a rule of thumb, if it's not leaking out the seal, it can't be moving about that much,

to ID if it's the front or rear diff pinion bearing, just put it in diff lock and pull one prop off at a time,

99% of the time neither of the above are the problem, it's the fact the customer has put a suspension lift one which the customer never wants to accept and we always get the answer, 2 things :

1) 'it didn't do it before I fitted the new transfer case', to understand my reasoning for this you need to understand how prop UJ's work, during each revolution the prop accelerates and decelerates so the speed looks like a sine wave for each rev, a worn transfer case allows this speed oscillation to 'hide' in the backlash but if you tighten up the driveline theres nowhere for it to hide and this results in a vibration, the bigger the lift the bigget the UJ angles the higher the speed difference the bigger the vibration,

2) 'but I've fitted high angle props', this makes no difference to the above, it just means the UJ's will not bottom out due to the increased angles, fitting a double cardan joint like the D2 will help as I think the double joint reduces the sine wave height.

hope this helps

Dave

[Maverik]

Aside from the vibrations, yes the vehicle does have a bit of a lift (not my doing - but I'm running with it for now).

I can grasp the front prop just forward of the flange joint and the output shaft moves up and down/ side to side. the is a bit of float along its axel direction, that I can account for as its a roller bearing.

The only reason I can see that it moves like this is play in the housing or the shaft where the roller bearing sits... failing that its the differential bearing that the shaft slots into or the shaft is a bad fit into the diff.

Irespective of whether or not the vehicle has a lift, the output shaft shouldn't move. I took off an old early LT77 with a 1.6 transfer box and I know thats been abused, but there's no float in the front shaft on this box.

Thanks for you input Dave, its not one of your boxes, I'm getting some support from the supplier but its really frustrating as I've only just fitted it! I know its a recon unit and we're talking Land rover's here but I work with rotating machinery and I'd be absolutly gobsmacked if this is an accurate example of acceptable tolerance.

[Maverik]

A wee update, I must have at least been talking some sense as I'm getting a new front main casing and internals being sent up to me.

Has anyone ever done an "in situe" front transfer box change-out?...