What are acceptable wear limits in power train

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Jason F

Active Member
Posts
111
Location
Sydney Australia
Hello, There has been lots of discussions re investigating backlash in drive train components, but have not found any pass fail criteria advice.
I have the same clunk some people complain about when the auto transmission catches up sometimes especially when braking down past 40km/hr.
I took it to auto box specialist and a differential specialist and a few mechanics, none were prepared to advise what is causing the problem without stripping everything down. The auto expert said its still moving up and down the gears very nicely, and did not recommend refurbishing the box.
The diff specialist said he does not think I will see any real value in re-building the diffs.
I did put heavy duty splined drive nuts on the front just in case its in the stub axles splines, but found no wear there.
So I decided to measure the angles myself this morning, as follows:
REAR: With hand brake on, 3.2 degrees movement.
FRONT: With hand brake on and auto in park, 8 degrees through CV and diff.
FRONT: With hand brake on and auto in park, 9.6 degrees through transfer case.
Total for FRONT is 17.6 degrees.
Is this a lot? I have no idea?
 
Stating obvious I know but have you tried putting handbrake on and rocking it back and forth using drive? Have a second person near diff, flanges, trans box , a frame etccc to listen for source of clunk. Its not hard to find doing this. But, it will probably be minor wear in several things. My flanges and a frame were the major issue. After 170k the diffs and halfshafts are fine.
 
you might want to drop t/box sump plate off and see if theres any play in intermediate gear ,it can be removed by tighten the nut on the outside, a lot of play is likely to be in center diff but without stripping the box not much you can do , auto boxes do get wear in the teeth/castellations that secure clutch baskets together but again little you can do and will run for many years as such
 
JM, presumably this is exactly the same on the manual? Can you provide our link to any more info on this please?

manual can have input gear and main shaft spline wear if its not a cross drilled fitted, transfer box issues relate to both manual and auto , what do you want to know ,i cant give you a link to whats in my head
 
he had the ears for that kind of stuff though:D

And he could have teleported over and had a look at the blokes motor! :D

OP, if the trans changes and drives fine, and it is meeting your needs of the vehicle, I would leave well alone. Just change the fluid every year or so. They are tough things, and as James said, will run for years with a few minor noises.
 
well i had terrible clunking in my 71 rrc auto..
to which i have just replaced both diffs, all halfshafts and cv;s,,uprated them to 24 splines..(so also changed hubs and stub axles so they would fit..)
much better, but still there on engaging reverse and dropping from 2nd to 1st..
however now as smooth as a bentley..due to playing with the line pressure maps on low map and speed in gearbox ecu..
yes i know you cant do that on yours..so..

my next mission will be to acquire another transfer box and rebuild that..as james stated i expect center diff wear..(gauging by how fecked the rear diff was)

james, you state the play in intermediate gear ..how much is exceptable, and is it adjustable out on all 230's?mine is real early 1.003:1..it may not have tapper roller bearings (if memory serves me)..

and cannot the center diff be removed insitu?(or is that memory a dream)
 
Thanks gents.
Greetings from Oz.
Yes I do like them. They are very solid and one can actually work on them. I will try the two person rocking the car method to try and find the loudest klunk.
Before I change oil, do you think its worth my taking the PTO plate off and having a look.
Ed's January post states that the gear will only pull out on 1.667 and 1.410 ratio boxes, 1.222 ratio boxes need the intermediate shaft to be aligned before removal and the 1.003 ratio unit cannot be withdrawn in situ on the vehicle. Even if I can get it out, I'm not sure if I can assess what wear there is on the bearings or the gear splines or to set up preload if new bearings needed? If the removable gear is worn, I suppose so is the mating gear/shaft in the box and perhaps many others ?
Sounds like all I can do is look to see if I have either the cross drilled shaft or oil feed plate I have been reading about. If the answer is yes, put it back and forget it? My vehicle was built Sept 95 does anyone know what my ratio is?
Do you think if I took the gear in to a dealer workshop that they could assess it ?
On the matter of my diffs, the front diff has more than twice the movement than the rear (but there are CVs in the circuit, so maybe these contribute towards the slack).
I have only changed the semi fluid grease once in the 300,000km (a few years back).
Are there some guidelines as to when the rotational slack in the wheels is too much ?
Pulling the transfer case out is too big a job for me. Does anyone know if its stamped on the case somewhere if I have 230Q ?
 
Last edited:
well i had terrible clunking in my 71 rrc auto..
to which i have just replaced both diffs, all halfshafts and cv;s,,uprated them to 24 splines..(so also changed hubs and stub axles so they would fit..)
much better, but still there on engaging reverse and dropping from 2nd to 1st..
however now as smooth as a bentley..due to playing with the line pressure maps on low map and speed in gearbox ecu..
yes i know you cant do that on yours..so..

my next mission will be to acquire another transfer box and rebuild that..as james stated i expect center diff wear..(gauging by how fecked the rear diff was)

james, you state the play in intermediate gear ..how much is exceptable, and is it adjustable out on all 230's?mine is real early 1.003:1..it may not have tapper roller bearings (if memory serves me)..

and cannot the center diff be removed insitu?(or is that memory a dream)

if its a lt230 r with roller bearings 4 thou is about right you can get shims to go behind thrust washers
if its taper bearings then no freeplay at all
center diff can only be removed by removing front output housing unlike lt95s which can be done through rear output housing
 
if its a lt230 r with roller bearings 4 thou is about right you can get shims to go behind thrust washers
if its taper bearings then no freeplay at all
center diff can only be removed by removing front output housing unlike lt95s which can be done through rear output housing

its an r type..cant remember. long time since stripped one down, can one adjust with transferbox in situ..??

and so then, fiddly yes, but center diff is doeable in situ?
 
Thanks gents.
Greetings from Oz.
Yes I do like them. They are very solid and one can actually work on them. I will try the two person rocking the car method to try and find the loudest klunk.
Before I change oil, do you think its worth my taking the PTO plate off and having a look.
Ed's January post states that the gear will only pull out on 1.667 and 1.410 ratio boxes, 1.222 ratio boxes need the intermediate shaft to be aligned before removal and the 1.003 ratio unit cannot be withdrawn in situ on the vehicle. Even if I can get it out, I'm not sure if I can assess what wear there is on the bearings or the gear splines or to set up preload if new bearings needed? If the removable gear is worn, I suppose so is the mating gear/shaft in the box and perhaps many others ?
Sounds like all I can do is look to see if I have either the cross drilled shaft or oil feed plate I have been reading about. If the answer is yes, put it back and forget it? My vehicle was built Sept 95 does anyone know what my ratio is?
Do you think if I took the gear in to a dealer workshop that they could assess it ?
On the matter of my diffs, the front diff has more than twice the movement than the rear (but there are CVs in the circuit, so maybe these contribute towards the slack).
I have only changed the semi fluid grease once in the 300,000km (a few years back).
Are there some guidelines as to when the rotational slack in the wheels is too much ?
Pulling the transfer case out is too big a job for me. Does anyone know if its stamped on the case somewhere if I have 230Q ?

it would be easier to drop sump plate, yours should be 1.222 as all v8 and tdi discos ,q boxes didnt come out till the td5 and imo are weaker than 300 tdi boxes as teeth are finer
 
its an r type..cant remember. long time since stripped one down, can one adjust with transferbox in situ..??

and so then, fiddly yes, but center diff is doeable in situ?

yes you can remove /refit intermediate gear and shim thrust washers, youd need box off to to rebuild center diff
 
Quite interested in this my self, have just replaced both props (changed rear to 4 bolt) on my 300tdi and now have a clunk coming from what sounds like the front and back of the vehicle as I come on and off the power.

Would doing away with the rear rubber donut make a existing clunk noticeable
 
worth checking A frame ball joint too ,changing to 4 bolt flange may do that if theres wear in system , its a matter of checking everything , jacking wheels up and rotatng props by hand often indicates were wear is
 
Gents,
My drive flanges are good (new heavy duty), no slop. ''A'' frame ball joint new (adjustable). About to fit a new heavy duty donut (even though the existing seems fine).
I can roll the vehicle back and forth 1" when handbrake off and in D. Bit of a soft click from rear, middle, and front as each come up to their limits. Nothing loud or metallic, same sound as when I had the wheels jacked up and rotated them each to work out the wear angles.

1) Is the ''centre diff'' the gear that can be removed from behind the front PTO plate ?

2) What needs to be ''aligned'' in order to get a 1.222 ratio gear out via the front PTO cover ?

3) Seems theres nothing I can do but check if fitted with oil feed plate or drilled shaft and if neither, fit a oil feed plate and if ball rollers maybe fit some shims ?

4) Sounds like my year has a LT230R case ?

5) Whats the ''intermediate gear'' please ? and how do I get to it ?

6) Are there any adjustments that can be done in-situ behind the rectangular bulkhead plates ?

Sorry about all the questions, but I am keen to do what I can myself with the transfer case without having to have it removed.
 
1 no thats input gear
2 i wouldnt try if i was you
3 you could check with sump plate off
4 only pre 86 had lt230r all discos are lt230t with taper bearings which are adjusted by the nut
5 it sits between input gear and center diff with high and low gears, remove sump plate
6 you need to get underneath
 
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