Quagmire Posted November 3, 2011 Share Posted November 3, 2011 Two weeks ago I fitted an LT77 to my 90 that I rebuilt myself after the last box starting grabbing 4th and not wanting to come out easily. All was well with new box, and it has been bedding in nicely. Tonight I did my 500 mile oil change, and that went fine. Found nothing untoward in the oil, just fine iron filings stuck to the magnetic drain plug. Drove the 25miles home from my parents to my house, the shift was getting better all the time... I was actually beginning to enjoy driving it again. Until I got to a roundabout and wanted to go from 4th to 3rd. Found I was totally stuck in 4th. I was only a mile from home so have made it back and parked up, and no amount of jiggling can get it out of gear. Clutch in or out, engine on or off, transfer in low/neutral/high... Seeing as my last box did this , and my rebuilt box has been fine with not a single crunch or bang could this be something to do with the selector mechanism? This is the only part that is common to both boxes. Help! Thanks Jamie Quote Link to comment Share on other sites More sharing options...
Quagmire Posted November 6, 2011 Author Share Posted November 6, 2011 Update. Its not the shifter mech on top- took that off this morning and all is well there. The box itself is totally jammed for some reason... Quote Link to comment Share on other sites More sharing options...
simonr Posted November 10, 2011 Share Posted November 10, 2011 I think your only option is to dismantle it and see what has seized! You could try filling the selector housing with penetrating oil and likewise with the ports for the detent springs - as it's most likely to be the selector rods seized in their tubes as that's one of the likely spots for water ingress. Leave it over night then see if you can 'wiggle' the rod enough to free it up? Si Quote Link to comment Share on other sites More sharing options...
Quagmire Posted November 10, 2011 Author Share Posted November 10, 2011 Thanks for the reply Simon- was in dire need of a tumbleweed smiley until you came along Disassembled this evening. Look what I found: The little pawl thing had dropped out, think perhaps the synchro had shot up too far? Appears to have worn the selector fork as a result of it being held in that position. At least I hope thats the cause- it definitely didnt look like that when it went together! So any ideas why that might have happened? I don't think I replaced those bits on 4th- if they were worn I suppose they could get sloppy enough to allow this to happen? Quote Link to comment Share on other sites More sharing options...
ashtrans Posted November 11, 2011 Share Posted November 11, 2011 this part is UKC3530L, we have many problems with these due to them being too soft, so much so I recently conducted a small experiment, I bought some from 5 different sources including genuine and sent them for hardness checking, results were : Bearmach 146-154 HV Allmakes 139-153 HV Britpart 144-151 HV Genuine LR 127-135 HV Evolution 803-838 HV it turned out the evolution ones were genuine LR old stock, ie genuine when the 77 was in production, all the others inc genuine were aftermarket untreated mild steel, note genuine was about 10 times the price of the others and was the same aftermarket part, unfortunatly evolution don't have any more so I am having to make my own from another supplier, when you put it back together I would suggest getting some out of an old 77 and putting a file across them to check they are hard Dave Quote Link to comment Share on other sites More sharing options...
Quagmire Posted November 12, 2011 Author Share Posted November 12, 2011 Thanks for the heads-up Dave, I have some left which were included in the rebuild kit I bought from you on 05/09 this year- will these be the hard ones or not? Cheers Jamie Quote Link to comment Share on other sites More sharing options...
Range Rover Blues Posted November 12, 2011 Share Posted November 12, 2011 Is there no way of hardenning the new ones then? are they case hardened for example. Quote Link to comment Share on other sites More sharing options...
ashtrans Posted November 13, 2011 Share Posted November 13, 2011 Thanks for the heads-up Dave, I have some left which were included in the rebuild kit I bought from you on 05/09 this year- will these be the hard ones or not? Cheers Jamie probably not, I would not use them, Dave Quote Link to comment Share on other sites More sharing options...
ashtrans Posted November 13, 2011 Share Posted November 13, 2011 Is there no way of hardenning the new ones then? are they case hardened for example. not really, they are just mild steel Quote Link to comment Share on other sites More sharing options...
G4FUJ Posted November 13, 2011 Share Posted November 13, 2011 A pretty appalling state of affairs if they're all mild steel. I could understand it from a certain supplier, but the others? Not good. Don't suppose it's a batch that has slipped through the hardening process?? Cheers, Quote Link to comment Share on other sites More sharing options...
kellyv8 Posted November 13, 2011 Share Posted November 13, 2011 could you have it cryo treated, would that work? Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted November 13, 2011 Share Posted November 13, 2011 I imagine it's far easier to get them made out of the correct steel in the first place so they can be hardened properly than to 'fix' the ones currently available. Obviously not practical for the man in the street but a sensible route for Ashcrofts, especially as they have to warranty their finished boxes. As a side effect it also means there will be a source for the man in the street Assuming Dave decides to start selling the ones he has made that is. Quote Link to comment Share on other sites More sharing options...
sonoronos Posted January 6, 2014 Share Posted January 6, 2014 Hello...I'm suffering the same issue as the pictures attached show... Quagmire, did you find out the long term solution to this? How did you end up fixing this? New baulk rings, slippers, and springs? Was this a problem with input shaft freeplay? Quote Link to comment Share on other sites More sharing options...
sonoronos Posted January 6, 2014 Share Posted January 6, 2014 Here are my photos Quote Link to comment Share on other sites More sharing options...
Quagmire Posted January 9, 2014 Author Share Posted January 9, 2014 I got the parts I needed from another old box and it has been totally fine ever since. Quote Link to comment Share on other sites More sharing options...
sonoronos Posted February 28, 2018 Share Posted February 28, 2018 Update: I got replacement slipper pads from Ashcroft's and replacement parts from Carddocks. Rebuilt my gearbox in 2014. The gearbox has been running strong ever since. The reason why this happened to me was that I had a habit of resting my hand on my gear lever while in 4th gear. Doing this rapidly wears out the clutch fork and baulk ring. Once the baulk ring wears out, the synchro sleeve will over-travel and the slipper pads will jam the synchro sleeve. I don't do that anymore Quote Link to comment Share on other sites More sharing options...
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