J type overdrive output shaft oil leak

[cggs]

Slight seep from the output flange area of the overdrive on my Spitfire 1500. Does anyone know if the output shaft seal can be replaced in-situ or does the transmission have to come out?  I can imagine that pullers might be needed to get the flange off.  I suspect this is a forlorn hope....

[Colin Lindsay]

I'd guess - if it's anything like my GT6 - that by removing the rear tunnel cover panel this will give access to the end of the propshaft and the rear flange, so if there's room to drop the propshaft out of the way the flange can be drifted off and the seal replaced in situ from above. Beware the sharp edges of the bodywork, but it should be feasible unless there's some obstruction or other that I haven't thought of.

I've located a rather small pic on the Net that seems to me to show how accessible it all is, even with the black tunnel cover plate still attached so based on this I'd go for it.

[Pete Lewis]

The coupling is on a straight slined shaft and will pop off quite easily with a few light taps , hookmthenoldnseal out  tap a new in flush

Grease the coupling surface to aid not nipping the new seal, torqure the nut 

Top up any oli loss EP80/90  GL4  oil ionly

[yorkshire_spam]

I've done mine in-situ, it's awkward, but do-able. Much improved if you have a slide hammer for pulling the old seal out. As said by previous posters, output flange will come off relatively easily.

 

[NonMember]

We did the rear seal on Toby's original box in-situ many years ago. It's not too bad a job. Mind you, we were taking the propshaft out to be balanced at the same time, which improves access.

[cggs]

Thanks for all those comments. Seems like it's not as bad as I feared. Am really keen not to have to take off the main tunnel cover as unfortunately  I've just re-sealed it down.  Dropping the propshaft will be interesting as there is a 2 inch exhaust drainpipe running not far beneath it....

I think I may be inclined to let someone with  garage hoist to take on the job as grovelling under the car has lost what little appeal it ever had.

 

[Guest]

11 minutes ago, cggs said:

I think I may be inclined to let someone with  garage hoist to take on the job as grovelling under the car has lost what little appeal it ever had.

Looking back at the answers & advice that have been generously given, I get the impression that grovelling is not necessary and that the job can be done tackling it from the top. I think you will find that if the car goes to the garage they will veer towards removing the transmission tunnel as it is the easier job option.

By undoing the prop at the O/D end you should be able to drop it out of the way providing sufficient room to do the job, which is what I believe you were hoping to do, hence commissioning the thread ??

[Pete Lewis]

you cannot do this from under the car  the tunnel has to come off...again  sorry

Pete

[Bazza]

What size socket is the output flange nut? 
Having got the overdrive working on my MKIV, whilst taking it for a test drive with the gearbox tunnel still removed, revealed a leaking oil seal as described above.

Thanks 

Barry 

[68vitesse]

My spare J type overdrive output flange nut is 1⅛AF.

Regards

Paul

 

[Bazza]

1 hour ago, 68vitesse said:

My spare J type overdrive output flange nut is 1⅛AF.

Regards

Paul

 

Thanks Paul

[johny]

Barry have you got something to hold the flange as the nut can be done up pretty tight?

[Pete Lewis]

yes stick two old bolts in the coupling and jam a bar /lever in to hold the coupling from turning

Pete

[Bazza]

Thanks Johny and Pete

I was planning to utilise the old bolts, holes a bar to hold the flange still.

[Pete Lewis]

if you want to knowa lot more about  heres a link to Buckeye triumphs geabox/overdrive how to's   its aimed aat TR but much is relevant to all others 

https://www.buckeyetriumphs.org/gearbox?rq=overdrive

Pete

[Bazza]

2 hours ago, Pete Lewis said:

if you want to knowa lot more about  heres a link to Buckeye triumphs geabox/overdrive how to's   its aimed aat TR but much is relevant to all others 

https://www.buckeyetriumphs.org/gearbox?rq=overdrive

Pete

Thanks Pete

I saw you making reference to this site in a previous post and had already had a look. Your guidance is greatly appreciated 

Barry 

[haggis]

I just did the rear seal on my gt6 last weekend, used a price of angle iron about a foot long with two holes drilled in it and the floor rails as a stop, to get it off and torque up. Lathe cut a 24mm bit of scaffold pole and pushed it on with the flange to get it parallel in the housing and hey presto. I decided to undo the engine mounts and rear gearbox mounts and jack the gearbox up from underneath, seemed to work a treat and plenty of access, gearbox cover definitely needs to come out though and best tackled from on top as said previously. Just make sure the seal goes in flat (scaff tube helped me) 

good luck. Hag 

[Bazza]

22 hours ago, haggis said:

I just did the rear seal on my gt6 last weekend, used a price of angle iron about a foot long with two holes drilled in it and the floor rails as a stop, to get it off and torque up. Lathe cut a 24mm bit of scaffold pole and pushed it on with the flange to get it parallel in the housing and hey presto. I decided to undo the engine mounts and rear gearbox mounts and jack the gearbox up from underneath, seemed to work a treat and plenty of access, gearbox cover definitely needs to come out though and best tackled from on top as said previously. Just make sure the seal goes in flat (scaff tube helped me) 

good luck. Hag 

Hi Hag, thanks for the advice

[Bazza]

Hi 

Would really appreciate some advice.....

Have disconnected the prop shaft and moved it out of the way, as much as I can. Can just with some difficulty get the socket on, but there is no way I can then get a socket wrench on! 
Any advice as to how to manage this would be appreciated. Would shortening the socket be viable? 
A previous post made reference to undoing the rear gearbox mount and engine mount bolts.....which if need be I’d like to avoid doing but it needs must!

Thanks 

Barry

[Colin Lindsay]

20 minutes ago, Bazza said:

A previous post made reference to undoing the rear gearbox mount and engine mount bolts.....which if need be I’d like to avoid doing but it needs must!

The gearbox / engine unit is held to the chassis by two mounts at the rear of the gearbox and the main engine mounts on either side of the block. If you undo the rear mounts, and slacken off the engine mounting bolts to give a degree of movement, you can jack or lever the rear of the box up, without straining or twisting the engine mounts, so as to get straight access to the rear shaft nut. It's as simple as it sounds and believe me you'll have much better access. Just be careful of your fingers on the sharp edges of that tunnel - it can hurt or do a lot of damage.

[Pete Lewis]

agree undo the rear mount from its support plate  its the easiest , undo the nuts above is easy but you wont get the munt to disengage the studs 

its get under and undo the two bolts   mounting to support plate 

jack the geabox as high as possible  watch for rad hose stretch and fan fouls radiator.

to get more access drop the prop from the diff  and remove rearwards to  get wrench access if needed 

the coupling should pop off on an OD quite easily 

make sure you get a good purchase on the seal and lever it out , refit /tap it in keeping it flush 

put some grease on the seal lip and coupling when refitting 

Pete

[Bazza]

1 hour ago, Colin Lindsay said:

The gearbox / engine unit is held to the chassis by two mounts at the rear of the gearbox and the main engine mounts on either side of the block. If you undo the rear mounts, and slacken off the engine mounting bolts to give a degree of movement, you can jack or lever the rear of the box up, without straining or twisting the engine mounts, so as to get straight access to the rear shaft nut. It's as simple as it sounds and believe me you'll have much better access. Just be careful of your fingers on the sharp edges of that tunnel - it can hurt or do a lot of damage.

Hi Colin

Many thanks for the advice. 
It looks like I’ll be a jacking up the gearbox etc. I was planning to replace the engine mounts which are showing signs of perishing so this would seem an ideal opportunity. 

[Bazza]

1 hour ago, Pete Lewis said:

agree undo the rear mount from its support plate  its the easiest , undo the nuts above is easy but you wont get the munt to disengage the studs 

its get under and undo the two bolts   mounting to support plate 

jack the geabox as high as possible  watch for rad hose stretch and fan fouls radiator.

to get more access drop the prop from the diff  and remove rearwards to  get wrench access if needed 

the coupling should pop off on an OD quite easily 

make sure you get a good purchase on the seal and lever it out , refit /tap it in keeping it flush 

put some grease on the seal lip and coupling when refitting 

Pete

Many thanks for the advice Pete 
Hopefully raising the gearbox, will give me enough access to avoid having to disconnect the prop from the diff...

[Colin Lindsay]

1 hour ago, Bazza said:

Hi Colin

Many thanks for the advice. 
It looks like I’ll be a jacking up the gearbox etc. I was planning to replace the engine mounts which are showing signs of perishing so this would seem an ideal opportunity. 

Keep a long, thin, but strong screwdriver or pry bar handy; once the gearbox end clears the body slide it in under, between the gearbox rear extension and across the car floor from side to side, to keep it raised. It means you're not resting things on whatever you jacked the gearbox up with, and there's less danger of it moving and slipping off once you start to undo the nut or pull the seal out.

[Bazza]

Thanks Colin