poohbear Posted May 8, 2008 Share Posted May 8, 2008 Hi all, just bought a 2.5TD 90 as a do-er-upper, already repaired the majority of electrical gremlins and am now starting to get the mechanical bits in order. I was wondering if anyone can help with a query I have regarding the centre diff - I have been driving the truck on A roads and dual carraigeways for 3 weeks now and the gearbox seems fine with just first being hard to select occasionally. The only problem appears to be the fact that the diff-lock doesn't appear to work! There is a nice positive action when using the diff-lock lever in high ratio and a lighter action when selecting in low ratio however the diff-lock indicator does not come on. I have tested the indicator wiring and that is all fine - I can't work out a way to get the switch out through the transmission tunnel yet to test it, but I can see the selector arm moving when I try to go in and out of diff-lock. I jacked up the front offside wheel this evening and with the handbrake on and 1st selected I can rotate the front wheel freely whether I select the diff-lock or not! Surely with three wheels on the ground and the diff-lock engaged this should not be possible? Am I looking at replacing the transfer box or is there another explanation for this? I have had a trawl through the technical archives but can't find any threads relating to this problem - any help would be gratefully received before I start a search for a new box! p.s. - great forum, I have already learnt a huge amount from the site. Quote Link to comment Share on other sites More sharing options...
edmason Posted May 8, 2008 Share Posted May 8, 2008 Hi all,just bought a 2.5TD 90 as a do-er-upper, already repaired the majority of electrical gremlins and am now starting to get the mechanical bits in order. I was wondering if anyone can help with a query I have regarding the centre diff - I have been driving the truck on A roads and dual carraigeways for 3 weeks now and the gearbox seems fine with just first being hard to select occasionally. The only problem appears to be the fact that the diff-lock doesn't appear to work! There is a nice positive action when using the diff-lock lever in high ratio and a lighter action when selecting in low ratio however the diff-lock indicator does not come on. I have tested the indicator wiring and that is all fine - I can't work out a way to get the switch out through the transmission tunnel yet to test it, but I can see the selector arm moving when I try to go in and out of diff-lock. I jacked up the front offside wheel this evening and with the handbrake on and 1st selected I can rotate the front wheel freely whether I select the diff-lock or not! Surely with three wheels on the ground and the diff-lock engaged this should not be possible? Am I looking at replacing the transfer box or is there another explanation for this? I have had a trawl through the technical archives but can't find any threads relating to this problem - any help would be gratefully received before I start a search for a new box! p.s. - great forum, I have already learnt a huge amount from the site. Common problem on LRs where Diff-lock has never been used. From what you describe the diff-lock isn't engaging, but before you go any further, are you engaging diff-lock whilst moving? You can select whilst stationary, but it won't actually engage (or disengage) until you are moving, & can take a second or two to do so. Second, this is a Land Rover, so if it doesn't work first time, use more force. My recently acquired Defender needed a very hefty push to get the diff lock in & out, but I imagine its never been used. Its getting easier with use. When I get time to put it on the ramp I'll smother the linkage with WD40. I tend to shift in & out of Diff-lock, & from Hi to Low box when I'm crawling in traffic & getting bored, it exercises the mechanism, and its good practice trying to get smooth changes on the move. Quote Link to comment Share on other sites More sharing options...
poohbear Posted May 8, 2008 Author Share Posted May 8, 2008 This makes sense - the guy I bought the truck off only used it as a play thing at weekends. in fact looking at the MOT cert it has only covered just over 1000 miles in the last 10 months. the box does go into both high and low ratio easily enough and there is a definate action as if it is selecting something when I try to engage the diff-lock. It maybe that I am too cautious about winding the transmission up! I'll give it another go. Many thanks for the help Quote Link to comment Share on other sites More sharing options...
nas90 Posted May 8, 2008 Share Posted May 8, 2008 This makes sense - the guy I bought the truck off only used it as a play thing at weekends. in fact looking at the MOT cert it has only covered just over 1000 miles in the last 10 months.the box does go into both high and low ratio easily enough and there is a definate action as if it is selecting something when I try to engage the diff-lock. It maybe that I am too cautious about winding the transmission up! I'll give it another go. Many thanks for the help Don't use the centre difflock on Tarmac. Go find a bit of mud otherwise you WILL be buying another transfer box having 'wound up' the transmission Quote Link to comment Share on other sites More sharing options...
mike4444244 Posted May 9, 2008 Share Posted May 9, 2008 Hi take the transmission tunnel off and make sure you are actually engaging diff lock, mud excess soundproofing and worn bushes can all interfere with the linkage, if you move the lever into lock watch the lever on the box and make sure its moving all the way over. Mike Quote Link to comment Share on other sites More sharing options...
poohbear Posted May 9, 2008 Author Share Posted May 9, 2008 Thanks for the input - will heed tarmac and diff lock warning! have tried to engage diff-lock this morning on grass - no indicator, and when performing full lock turns it appears that the diff is not locked as all the wheels turn freely without digging any grass up! Still goes in to hi & lo fine whether stationary or moving and the selector arm is definately moving on the transfer box as I can see it. There is however quite a bit of play in the linkage between the lever and selector arm. The guy I brought it off said that he had replaced part of the transmission following a long drive from Wales to the midlands. I'm guessing that this is the nice shiny new bit of casing which I can see between the main box (LT77) and the transfer box, can anyone tell me what this is? If this drive had been done with the diff locked what would be the symptons? Once I get this sorted i'll be happy to get the truck off the tarmac and use it properly! Quote Link to comment Share on other sites More sharing options...
V8mule Posted May 9, 2008 Share Posted May 9, 2008 sorry to say but unless read your post wrong your only selecting hi and low range not engaging the diff, to engage the center diff you need to move the leaver to the left and disengage move it back to the right. to check the diff is working just jack up 1 front wheel (hand brake on) with the diff disengaged (leaver to the the right) the wheel shoud spin, "on road use" engage the diff (leaver to the left and the warning light should come on) the wheel shouldn't spin "off road only and only then when you nead it" Ian Quote Link to comment Share on other sites More sharing options...
poohbear Posted May 9, 2008 Author Share Posted May 9, 2008 Thanks for that V8mule - managed to solve the problem over my lunch hour. It turns out that although the transfer box selector linkage was moving, there was that much slop in the system that it wasn't throwing the selector arm far enough over. I have solved the problem temporarily by moving the centre pivot point out which has made up for the slack in the system - I now have fully working diff lock with the indicator confirming this! I'll get some new pins and bits next week to replace all the parts between the lever and the transfer box selector arm - that should solve the problem for good! Thanks to mike44424 for the tip Also thanks to all who took the time to post a reply! Quote Link to comment Share on other sites More sharing options...
mike4444244 Posted May 9, 2008 Share Posted May 9, 2008 Glad you got it sorted! I had the same problem but due to someone stuffing loads of soundproofing down the side of the linkage! Mike Quote Link to comment Share on other sites More sharing options...
101sean Posted May 9, 2008 Share Posted May 9, 2008 There will probably be a load of plastic top hat bushes missing from the various pivot points, FRC4499 I think. Just replaced all mine after several went walkabout when putting new boxes in. It's a fairly wobbly arrangement that looks like it was drawn up on a fag packet, needs all the slack taken out to work. Quote Link to comment Share on other sites More sharing options...
western Posted May 9, 2008 Share Posted May 9, 2008 might be worth getting these bits to replace any worn/broken ones spring clip FRC3674 bush FRC4499 Quote Link to comment Share on other sites More sharing options...
poohbear Posted May 9, 2008 Author Share Posted May 9, 2008 101sean - Plastic bushes There were no bits of plastic down there at all! That would explain why there is so much play. Still got it working for the moment. Western - thanks for the codes - will add them to the ever increasing shopping list. Quote Link to comment Share on other sites More sharing options...
western Posted May 9, 2008 Share Posted May 9, 2008 101sean - Plastic bushes There were no bits of plastic down there at all! That would explain why there is so much play. Still got it working for the moment. Western - thanks for the codes - will add them to the ever increasing shopping list. Bushes highlighted Green Clips highlighted Red on the parts diagrams below for the hi/low range change/diff lock linkage. Quote Link to comment Share on other sites More sharing options...
Cat_J Posted May 9, 2008 Share Posted May 9, 2008 Thanks for the input - will heed tarmac and diff lock warning!have tried to engage diff-lock this morning on grass - no indicator, and when performing full lock turns it appears that the diff is not locked as all the wheels turn freely without digging any grass up! Still goes in to hi & lo fine whether stationary or moving and the selector arm is definately moving on the transfer box as I can see it. There is however quite a bit of play in the linkage between the lever and selector arm. The guy I brought it off said that he had replaced part of the transmission following a long drive from Wales to the midlands. I'm guessing that this is the nice shiny new bit of casing which I can see between the main box (LT77) and the transfer box, can anyone tell me what this is? If this drive had been done with the diff locked what would be the symptons? Once I get this sorted i'll be happy to get the truck off the tarmac and use it properly! Just to say I wouldn't use the diff-lock even on grass. The only situation I've used it in is in very lose mud and a river with a muddy base. There is still quite a lot of traction on grass/ Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted May 10, 2008 Share Posted May 10, 2008 There is still quite a lot of traction on grass Not on wet grass there isn't. Dry hard surfaces, be they grass, rock or tarmac then you shouldn't need or use difflock. Loose, slippery surfaces then go for it. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
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.