Howitzer Posted March 4, 2012 Share Posted March 4, 2012 A little history first.... The output shaft was badly worn so when my transfer box failed nearly 2 years ago now I had the main gearbox rebuilt aswell. This lasted around 3 to 4000 miles before developing a whine when slowing down after a long tow I did. The gearbox was removed and sent back to the refurbishers (They are known as a good lot and i've used them in the past) who said a bearing had failed and it was re-built under warranty. Now I just finished a 2 week norway trip and after between 3 and 4000 miles into the trip, probably 5000 in total since the rebuild I lost 5th gear going up a long climb. The engine was working but not excessively hard. Due to where we were we soldiered on and 1st, 2nd and 3rd gear made horrible rattling sounds but engaged fine, 5th wouldn't engage at all and 4th was still rattly but much much less than the first 3 gears. We covered 2000 miles like this driving back to the UK using 99% of the time only 4th. We pulled away in second till 20mph and then went straight to 4th, in the hills of Norway this really made the engine work at times. So, it's a mildly tuned 200tdi, just on boost fueling and boost raised slightly, I am sympathetic with the box, I used Ashcroft semi synthetic gear oil in the whole transmission and it has never felt better. Is the LT77 just not capable of high loads in 5th gear, I doubt very much if it wasn't, or is my gearbox chap just missing a trrick with these boxes somewhere? If I can find a manual i'll be building it myself this time or wimp out and send it to Ashcrofts. Considering how well the truck went the gearbox failing again has me wanting to fit an R380 or look at spending to do a 6 speed conversion, which i'd rather not do. Dave! Quote Link to comment Share on other sites More sharing options...
kiwi_110 Posted March 5, 2012 Share Posted March 5, 2012 Before my old 90 was V8'd, I was running a Nissan LD28 engine with the LT77. We did a lot of towing a double horse-box and never had an issue with the gearbox. I think the LT77 is well capable of handling what you're doing and suspect something has not gone right with the reassembly or there has been a lube issue. I'd be using Dexron ATF. Quote Link to comment Share on other sites More sharing options...
Chicken Drumstick Posted March 6, 2012 Share Posted March 6, 2012 The LT-77/R380 are not the strongest of boxes, but should be handling what you are saying with ease. Quote Link to comment Share on other sites More sharing options...
Howitzer Posted March 8, 2012 Author Share Posted March 8, 2012 After talking to a transmission place he thinks the shaft that 5th runs on has snapped. I'll have the box out in a couple of days and we will be able to see then. Dave! Quote Link to comment Share on other sites More sharing options...
vulcan bomber Posted March 8, 2012 Share Posted March 8, 2012 A layshaft bearing has let go.. I destroyed an Lt77 when this happened to me. Sounds like your box hasnt been reshimmed when its been reconditioned. You'll find that when the box is out, the in put and out put shafts will flop about a heck of alot. 4th is quiet because its direct drive through the box, there for the lay shaft isnt taking any force, its still turning though. Quote Link to comment Share on other sites More sharing options...
vulcan bomber Posted March 8, 2012 Share Posted March 8, 2012 A layshaft bearing has let go.. I destroyed an Lt77 when this happened to me. Sounds like your box hasnt been reshimmed when its been reconditioned. You'll find that when the box is out, the in put and out put shafts will flop about a heck of alot. 4th is quiet because its direct drive through the box, there for the lay shaft isnt taking any force, its still turning though. Quote Link to comment Share on other sites More sharing options...
vulcan bomber Posted March 8, 2012 Share Posted March 8, 2012 A layshaft bearing has let go.. I destroyed an Lt77 when this happened to me. Sounds like your box hasnt been reshimmed when its been reconditioned. You'll find that when the box is out, the in put and out put shafts will flop about a heck of alot. 4th is quiet because its direct drive through the box, there for the lay shaft isnt taking any force, its still turning though. 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.