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1500 o/d gearbox problems


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Hello all.

Driving my '76 Spitfire 1500 last weekend and after 20 years of ownership, the (o/d) gearbox  starts playing up for the first time.

Goes into gear ok (all gears) but sticks in 3/2/1... I have to really yank on the lever to get it out of gear, especially in 3rd.. any ideas?

I am thinking that i'm going to have to fetch the box out to take a look and, well probably a recon box is the only sensible option (?).

I think that it may be time to do that bottom-end engine rebuild at the same time... (yes, it really needs it!)

Any thoughts on expected costs for an engine-gearbox transplant? any recommendations for reputable suppliers?

All thoughts gratefully received.

Regards,

Alex.

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If you  select gears on the drive, what happens if you engage disengage with the engine off., but sticks with it running

Then its a clutch problem.

Being a 76 1500 this is single rail gearbox?

Have you lubricated the gear stick ball and socket ??

Pete

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Don't rush into having a new gearbox. Unless you go to the top people (Mike Papworth, etc.) then you may end up with something worse!

Sticking in those gears - in addition to Pete's advice, does it do this all the time or only when hot?

I'm guessing your engine is a bit rattly, right, and you're thinking new bearings? This can be done in situ if the gearbox doesn't need to come out.

What I'm saying is, diagnose the problems rather than assuming a new gearbox/engine will solve things - they may bring a raft of new problems instead! Been there - got the T-shirt.

Cheers, Richard

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1 hour ago, rlubikey said:

Don't rush into having a new gearbox. Unless you go to the top people (Mike Papworth, etc.) then you may end up with something worse!

Last time I enquired about having a 1200 gearbox rebuilt I was told that many of the components are now unavailable and the only option is to reuse the customer's own components whilst replacing the bits that are available. I decided against it.

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Hi all. Thanks for the replies. 

it sticks all the time hot or cold But sat here in the driveway with the engine stopped it seems to be able to go into all the four gears and out again without any trouble  irrespective of whether the clutch is in or out.  Also it goes in and out of reverse with the engine running no problem at all is this still pointing to a clutch problem or gearbox do you think ?

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I would start buy pop the gearstick out and grease the spherical ball and inspect it for wear or cracks

Do the simple cheap first

If you can engage ok with engine off but not if idleing that suggests clutch but with no grating of teeth getting reverse say not.

Do the easy first.

Pete

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  • 2 weeks later...

Hi all. Thanks for the replies. 

 Taking your advice I have withdrawn the gearstick clean things up a bit and think I may have found the problem   Looking at the attached picture of the pin on the right hand side May have come loose and prevented the gearstick from locating properly could this be the problem?  You’ll see that it can fairly easily be fully removed and that there is some significant wear in the slot on the ball joint of the gearstick  

FA22A293-A962-4F05-A5E4-E991B6D6C196.jpeg

2AA8E5DB-FF07-4D99-91B0-6CC66D20B69B.jpeg

EB91B96E-B6F1-45AE-931E-6832D9FDCC6C.jpeg

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I think you may have it! If it was fairly easy to remove the question is, will it go back tight and stay in place? If not, some clever Heath Robinson may be required, or failing that a new gearbox extension.

Cheers, Richard

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All greased and reassembled but problem persisting. I did notice that when it stuck in third, the only way to get it back out again was to release the clutch (thereby stalling the engine) then disengaging g third gear, restart engine , apologise to traffic queue behind me and limp home. 

Will strip down again tomorrow and take a look to see if the pin has moved again but am wondering if the wear in the slot on the ball joint is the real problem ( see pic above) ... I assume that this should be nice and straight. 

Also took the opportunity to replace the gearbox oil at the same time and as expected it was nice and clean. 

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Hi all. So I disassembled the Gearstick again and refitted the pin ( which had previously worked loose ) with some bearing fit And took it out for another test drive.  With the engine off I can select and disengage from all four gears ... Same with the engine idling on the driveway.  For the first few minutes of our run it seem to be going in and out of gears without too much problem  But after five minutes of going up and down the box it will not  disengage from third gear and I have trouble getting it into second gear. 

Could this be the clutch I am really not sure there  is certainly no sign of it slipping but I don’t know how to check whether it is adjusted properly or even whether it is possible to adjust this clutch. 

 

Alex

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A clutch thats not disengaging fully is certainly something which could produce symptoms like yours although I would expect it to give problems in all gears especially 1st when stationary. Theyre not adjustable but obviously you should check the clutch reservoir fluid level if you havent already done that and also try pumping the clutch pedal a few times quickly before selecting or disengaging a gear. Its possible you have a seal in the system thats not doing its job properly (getting worse with use/temperature) and by pumping you can temporarily get sufficient pressure for the clutch to separate enough to allow the gear change. Let us know if this works and if not we'll have a think as to what else it could be.....

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On 28/05/2019 at 17:18, iana said:

Pete just noticed your suggesting greasing the gear lever ball, is this the black plastic bush on the vitesse (if so what do you recommend as I could find any reference to grease or oil etc)

If you are talking about the nylon ball that sits in the gearchange extension of the three rail gearbox personally I would never grease it as grease plus grit can wear the aluminium socket.

Regards

Paul

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after 50 years of gear changes  it a bit late to worry now , whilst plastic  and alloy cant seize together a dosh of lube keeps things sweet, old addage .......... if it moves  oil it   

the modern plastic replacements are pretty inferior to the originals, if you find a NOS  metal one get it, you may induce gear lever sizzle 

but it wont break up 

metal  was  120570    cant see any anywhere 

plastic   was 138685   generally available in all the remote kits

Pete

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The gear levers seem to be hard to come by but do come up on ebay from time to time but obviously arent cheap.

Why not try some experimenting with the clutch before replacing everything. You can also check under the master cylinder rubber covers for a leak and then carefully watch the level in the reservoir while an assistant presses the pedal (if it increases at all then the mc has a problem)..... 

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i have a overdrive version , there is small wear to the slot nothing like yours exhibits 

theres non od on on ebay at £15 just now.

i would not have thought that level  of wear that  yours shows   would lock gears 

think you need to examine further

Pete

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