Jump to content

transfer box getting hot


Recommended Posts

Hi all,

Mate of mines just swapped his input gear on his transfer box for one from ashcrofts ( cross drilled )

He basically:

removed PTO cover,

Removed old gear

Fitted new input gear

Replaced cover.

He left the original races, as they were in perfect condition.

its noticeably hot at the top of the transfer box! :o

Has he missed anything?

Thanks in advance

Link to comment
Share on other sites

Hotter than it was before or just that it's suddenly been noticed because people are looking?

Good point, said the same to him, however he said its hotter than before...

(do they get hot there? Ive never checked)

Link to comment
Share on other sites

squirt some water at it and see if and where the water turns to steam then you know 2 things, one its 100deg + which is not normal and 2 the area that is warmest suggesting a problem area.

It took me 14hrs to drive Sheff to Aberdeen as transfer box kept overheating, turned out to be a compounded problem between 2 U joints on the front prop fwd where solid and the rear prop expansion splines where solid too, caused the whole transmission to get stressed out a bit. Lots of steam was like a sauner in the cab...

Link to comment
Share on other sites

Hi,

It is my car that this applies too :) I wasnt around last night so asked Grant to put it up for me

The heat is centralising around the top part of the transfer box, after about 1 mile the area around the input gear is hot to the touch but not scaulding, I have also noticed a slight whine.

Could it be that the PTO cover bolts act as pre-load on the bearing and I have done them up too tight?

Adam

Link to comment
Share on other sites

Yeah, brand new and prepp'd by ashcroft, bearings were also pressed in by them, transfer box slipped straight on, no problems.

I'm trying to work out whether transfer boxes have some sort of shim or torque to control pre-load, but i'm struggling to find information

Link to comment
Share on other sites

Preload is set by shims in the bearing holder - the first bit of alloy that you screw onto the transfer box before you bolt the PTO cover on. The shims sit behind the bearing race. The torque you set the screws and bolts to and the gasket between the alloy bearing casing and the transfer box are vital in setting the preload correctly. My suspicion is that you have the preload set wrong, perhaps the gasket missing (replaced with liquid sealant?) and the torque incorrect on the PTO cover bolts. If all/most of these are wrong, the input gear and its bearings will be too tight and this could explain the heat. The preload can be measured in place using a dial gauge, but it is not easy to do this accurately in my experience.

Grant, when you heading this way for the flywheel housing????

Link to comment
Share on other sites

As discussed here:

http://forums.lr4x4.com/index.php?showtopic=48673

I don't think that you need to worry about re-shimming the transfer box bearings, even if you replace the bearings.

By far the most likely cause of incorrect pre-load on the bearings (which I agree is the most likely cause of any extra heating in this case) is the absence of the cover plate and bearing carrier gaskets. Try a set of new, clean gaskets (don't use sealant, the real things are cheap as chips: http://cgi.ebay.co.uk/LT230-PTO-COVER-GASKET-/260595845809) and see if the problem goes away.

Nick.

Link to comment
Share on other sites

Ok now I am a bit annoyed, I told ashcroft to supply me with everything I need and they said all I need to do was remove the old on and put theirs in. Hmm not all they are cracked up to be it seems

You are correct, I have used sealant as per ashcrofts instruction, I wont be able to get the correct seals before the weekend, any quick fixes anyone can think of?

Adam

Link to comment
Share on other sites

Sort out the bearing tracks first. Clean the gasket faces on the transfer box and bearing carrier. Assemble bits in to transfer box and lightly hold the bearing carrier in place (a couple of bolts could act as guides to locate) - is there a gap between the bearing carrier and mating face on the transfer box? If so, this will be the amount of preload you will apply to the bearings.

IIRC, liquid gaskets were introduced from the 300Tdi onward (mid 1994). Gaskets can be cut from cardboard (cereal packet). Apply a reasonable coating of general purpose grease to both faces and assemble as normal. This should remain leak free for some considerable time, and certainly long enough to source some genuine articles.

Link to comment
Share on other sites

When you consider the tiny difference in thickness of the shims used behind the race on the carrier to set the pre-load, you realise how important the gasket and its thickness could be. You only need the gasket between the bearing race carrier and the transfer box body. The PTO cover can be replaced using liquid sealant as the pto cover doesnt have an effect on the preload. It is really important the bolts are done up to the correct torque though - have you done them and the two countersunk screws up to 25nm - this isnt all that tight, so its easy to overtighten if you dont use a torque wrench.

HTH

Link to comment
Share on other sites

I don't know if you have tried this and it's a bit radical but rather than bitching about it on an internet forum, have you tried phoning Ashcrofts and discussing it?

Currently we don't even know if it's just a bit different than it was before or even exactly the same but you never noticed. The top may well get hotter because the bottom is full of oil, I don't know anyone who's ever measured the difference.

Link to comment
Share on other sites

Not meaning to bitch, I just havent had a chance inside of opening hours to contact ashcroft about it, but I did ask them to explain the procedure over the phone, but that wasn't correct.

Unfortunately I don't have the tools to get to the inner race just now, so will check the preload and do the outer race today, i'll report back to see if that has helped

thanks :)

Link to comment
Share on other sites

Box has to come off to change the inner race really, thats why most people dont worry about them a lot of the time. Use a gasket and torque the bolts correctly and see if that makes any difference. If you phone ashcorfts now, there may be someone there. But as others have said, i guess it may be running fine as the boxes do get hot under use. If you need it i have an LT230 overhaul manual somewhere - i cant remember the original link, but can send you a pdf copy if you pm me your email address.

Link to comment
Share on other sites

I've done the best in the time available, Fitted the new outer race, checked the shim size and re-assembled without the pto cover, measured the gap and made a suitable cardboard gasket, once torqued the play in the shaft just goes away, then put it all back together. I am hoping that will survive ok until I can rip the TB back out early next week

Adam

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy