denviks Posted October 23, 2008 Share Posted October 23, 2008 Morning all. I have just hit a strange problem with my 1991 110. we have just carried out a tdi conversion from a TD set up. It all went very well indeed. We made everything to fit and only had to buy a small piece of metal tubing to extend a couple of hoses. That was it. Anyway on to my problem of such. After running the engine up I took it down the road yesterday for its maiden run. The gears were like a blummin race car…..short. it was like being in low range but topping out at 65 mph ish…. ( shows 70 mph on the Speedo ) but I know that isn’t correct . Would my problem be the gearbox or as I suspect the transfer box. Everyone I have spoke to said that when theirs was done they didn’t have any problems and could use the defender transfer box …. Just a little confused now….. Is there 3 types of transfere box or is the lt77 different in the earlier defenders ? Any help and advice would be brilliant Quote Link to comment Share on other sites More sharing options...
Pete Attryde Posted October 23, 2008 Share Posted October 23, 2008 I believe There are Four ratio's of LT230 transfer box. 1.6:1 which I believe was fitted to early 110's 1.4:1 fitted to most 90/110/defenders 1.2:1 fitted to most Discoverys and Range Rovers 1.001:1 fitted to some three speed Range Rovers all the low ratio's are the same. The lower the number the higher the speed for a given RPM. Pete. I suspect you have a 1.6:1 box, where as a 1.4:1 box might be more suitable. Quote Link to comment Share on other sites More sharing options...
denviks Posted October 23, 2008 Author Share Posted October 23, 2008 thanks pete. that makes perfect scense now.... looks like a transfer box change looming soon then Quote Link to comment Share on other sites More sharing options...
reb78 Posted October 23, 2008 Share Posted October 23, 2008 Your problem could be the old LT77 gearbox that was coupled to the TD engine. The ratios in 5th are different to those on the later LT77s which was fitted to the 200tdi engines. The LT77s has a slightly higher ratio so will allow more speed from the same revs http://members.shaw.ca/red90/gears.html shows you what the ratios are). Has your top speed changed from when you had the TD? Fitting a 1.2:1 ratio transfer box is a way around this without changing the gearbox, but the gearbox has probably suffered the same mainshaft wear as mine, so it might be time to replace it anyway... Quote Link to comment Share on other sites More sharing options...
denviks Posted October 23, 2008 Author Share Posted October 23, 2008 Your problem could be the old LT77 gearbox that was coupled to the TD engine. The ratios in 5th are different to those on the later LT77s which was fitted to the 200tdi engines. The LT77s has a slightly higher ratio so will allow more speed from the same revs (http://members.shaw.ca/red90/gears.html shows you what the ratios are). Has your top speed changed from when you had the TD?Fitting a 1.2:1 ratio transfer box is a way around this without changing the gearbox, but the gearbox has probably suffered the same mainshaft wear as mine, so it might be time to replace it anyway... do you know what. i dont think the top speed is much higher than before...... it just gets there alot faster and holds it well. the gearbox has less than 9k on it as it was a recon box and transfer box fitted 2 years ago so now just about run in Quote Link to comment Share on other sites More sharing options...
Guest diesel_jim Posted October 23, 2008 Share Posted October 23, 2008 Sounds like you've got a 1.6:1 box under there....crawl under and get the serial number off of it, we can tell what it is then. On my old 90 (was a 200Tdi), when i fitted "big" 255/85/16's years back (still very wet behind the ears) i didn't know about tweeking the fuelling and stuff, so i fitted a 1.6:1 to try and alleviate the gearing issues.... it went just like yours.... a gocart up to 65, then the valves were bouncing trying to get 70mph. go for a 1.4:1. 'nuff said. Quote Link to comment Share on other sites More sharing options...
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