How to fix 1850 od box, noisy 1st to 3rd?

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GTS290N
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How to fix 1850 od box, noisy 1st to 3rd?

#1 Post by GTS290N »

Hi All,

I have an 1850 single rail overdrive box which is very very noisy, it growls, in first through third, it's OK in 4th.
Is there an eejits guide to fix this? How hard is it? Are the parts available?
Never been inside a gearbox.....
The box on my car is notchy when cold, can be difficukt to find first, crunches from first to second, leaks like the Exxon Valdiz but doesn't growl..........
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xvivalve
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Re: How to fix 1850 od box, noisy 1st to 3rd?

#2 Post by xvivalve »

That will be worn bearings on the layshaft.

Parts are available, but you have to watch quality and metric equivalents of imperial and the like. Jon Tilson may be able to advise in greater detail
Jon Tilson
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Re: How to fix 1850 od box, noisy 1st to 3rd?

#3 Post by Jon Tilson »

You will find the layshaft is knackered.
On a dolly 1850 box the cheapest way out is to rebuild it with a TR7 4 speed layshaft which is about 1/3 the price
(havent looked for a while) and available new old stock from Rimmer Bros. You also need to swap 2ng gear synchro hub and a reverse idler to match it. I have those bits about as I use old non o-d boxes from ohv cars which yield some supply. Its also cheaper to buy the idler and layshaft than the 1850 one....and get the synhco hub 2nd hand.

You then need a new lay pin and the needle rollers, which you dont buy from Rimmers cos they sell you metric equivalents and
a lay pin that isnt hard enough.
Get those bits from Fitchetts or Canley Classics and be VERY careful about what you buy. You can also get stuff from Moss. They do
build boxes up and Adam there knows his onions.

You could buy one from me already done and I would want 450 quid, but I don't have one done at the moment and the next one I do
is going in my spit. Sorry....so your probably looking at 6 months or more. That gives me an hourly rate of about 50p by the time I get the bits btw...

By all means try it yourself. You will need quality circlip pliers and a lot of patience. Your other option is an exchange from Mike Papworth. I cant personally recommend anyone else but that's not to say Fitchtetts won't also have something decent.

Jonners
Note from Admin: sadly Jon passed away in February 2018 but his humour and wealth of knowledge will be fondly remembered by all. RIP Jonners.
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