• Hi Guest! Being a Paying Supporter is NOT a requirement to participate at BCF. However, subscribing will help ensure we can continue to serve the LBC community for years to come. If you enjoy BCF and find our forum a useful resource...Please consider supporting us by **Upgrading**
    (PS: Subscribers don't see this banner)
Tips
Tips

TR6 Transmission Oil Seal

EWD

Senior Member
Country flag
Offline
Hi folks,
Just found the source of the oil leak on my 74 TR6 - behind the shifter in front of the U joint. It has obviously been leaking awhile and when I put it up on jacks ( for over a month while rebuilding the front end), the leak worsened with the transmission oil heading south. Is there an easy fix to this? At this point, I have not started on my interior and the trans cover is off.
Thanks,
Will
 

CJD

Yoda
Country flag
Offline
I know the shifter can leak...and the rear seal can leak...but I'm not sure what can leak in between those.

The shifter levers have 3 0ring seals that are common leaks, which would come out in the area you are describing. Being at the top of the tranny, though, they would leak less when the tranny is not spinning.

The rear seal would leak straight down onto the cross-member, and blow rearward from there. It will leak running or not.

The speedo drive gear is in that area, left side on a straight tranny and right on an OD. It uses an o-ring for the hub and another for the internal drive shaft. It would also leak at all times, running or not.

The gasket for the tailhousing or OD is another source of leakage, but a bit forward of where you describe. Of course, if you have an OD there are multiple additional sources of leaks.

Finally, most tail housings have a vent hole. It will be on the top, and would not leak when the tranny is idle...but if it gets plugged it is possible it would cause an internal pressure to cause other leaks.

That's all I have got...if you have a picture I might be able to help narrow it down more...
 

poolboy

Yoda
Country flag
Offline
I stuck a pin into that vent on my transmission in order to show it's location in this picture...it's small.
TR6Trannyvent.jpg
 
OP
E

EWD

Senior Member
Country flag
Offline
Thanks guys. I think it’s the rear seal as it drips down to the cross member right below and blows back. Will try to find and clear the vent hole. So, if it is the rear seal, I imagine the leak will diminish when the car is again level (it leaked before). Wonder if it is worth the effort to fix. Shifting appears ok but have only driven it a few miles.
 

Madflyer

Jedi Knight
Country flag
Offline
Will As I look at pic of the TR 6 trans would it not be at the end of the output shaft flange seal before the U joint ?? If you just have the front of the car up then even more oil from trans. would leak to rear. I will be pulling my trans. this week for leaks and new clutch assy. You may be able to split drive line from trans. and lift trans from rear mount remove flange and replace seal This is from memory will be into it soon. There are ball bearings at either end of tail shaft so oil is in to oil that rear bearing. Madflyer
 
OP
E

EWD

Senior Member
Country flag
Offline
Madflyer -
Just came in from the garage. Yes, before the Ubolt. I put a coffee lid under the area last night to verify the source. Also yes re: an increased oil leak due to the jacked tilt (jacked on both sides). I was under the car cleaning the area and could tell from the crud, that it has been leaking for some time, I just don’t know how much. I topped off the oil before I started the front end rebuild. It took a lot of oil (filled to the bottom of the threads as suggested); so it was low. The previous owner had never checked the oil level and it had not been driven very much in years ( I noticed a small leak area in his garage as well). Anyway, that’s where I am at this point. Thx.
 

Madflyer

Jedi Knight
Country flag
Offline
Will if you do change that seal look at the flange before putting it back for any thing rough you will see where the seal was before. That seal can be set in or out a bit so it could run in a different spot if need be. not that easy to take out as I remember a hammer and small block of wood to install and adjust to flange. Not all leaks are bad some prevent rust. Madflyer
 
OP
E

EWD

Senior Member
Country flag
Offline
Good advice. At this point, I think I’ll monitor after car is level. Thx for your help.
Will
 

CJD

Yoda
Country flag
Offline
You can always think of the slight leak as an “automatic oiler” for the rear of the car?!? As long as I don’t have to service any fluid levels between oil changes I am usually pretty tolerant of leaks.

If the tunnel is off, that seal isn’t too bad to get to. 4 nuts removes the drive shaft, which should push rearward enough to reach the large center bolt for the yoke. The tranny in 1st will give it enough drag from the engine to loosen the large nut. Normally the yoke will then be a slip fit, but sometimes it needs some coaxing with wooden hammer or puller. You then have access to the seal. Just be careful not to scratch the drive shaft pulling the old seal out with a flat blade screwdriver, if you don’t have a seal puller.
 

Madflyer

Jedi Knight
Country flag
Offline
Will I just got done pulling my trans. And as John says It should be fairly easy to change seal. looks like the rubber mounts at the rear tale shaft would need to be replaced also. Some leaks are more work than the leaks its self need to be worth the fix. and some leaks just go behind a tree. Madflyer
 
OP
E

EWD

Senior Member
Country flag
Offline
I’m just going behind the tree until I find a bigger stream. Hopefully I’ll be level again soon.
Thx
 

Madflyer

Jedi Knight
Country flag
Offline
Tran. back in should test drive today all seals easy work new clutch and pressure plate and bearing and bushing. Old clutch was LUK not in bad shape after 15 plus years The B&B fell apart in a few years. My disk had maybe 50% left not down to rivets. New windscreen next. Madflyer
 

Madflyer

Jedi Knight
Country flag
Offline
Thanks for the call Will any time.

Ran car and put cardboard under trans and motor sat over night no leaks. Madflyer
 
Similar threads
Thread starter Title Forum Replies Date
G Changing front oil seal on transmission. Triumph 14
S TR2/3/3A What weight transmission oil in a tr3 with OD? Triumph 13
TomMull TR2/3/3A Transmission oil leak Triumph 17
G Transmission with Overdrive - Which Oil to Use Austin Healey 30
vette Transmission Oil Austin Healey 5
M What is the proper oil for Bugeye engne and transmission Spridgets 6
PAUL161 MGB MGB Transmission Oil Capacity ? MG 2
T Transmission Oil Austin Healey 7
R transmission and rear end oil Austin Healey 2
P TR2/3/3A TR3 Transmission oil Triumph 13
bobh Changing Transmission Oil in 10 minutes Triumph 8
T TR2/3/3A What weight gear oil to use in TR3 transmission? Triumph 23
T 1275 transmission oil leak Spridgets 2
M Transmission oil Spridgets 2
Jim_Gruber Transmission Oil and Differential Spridgets 3
J location of transmission oil filler on a BN-2 Austin Healey 5
PAUL161 Transmission oil Type MG 3
ekamm TR2/3/3A tr3a transmission oil preferences? Triumph 4
TRnorwegian Easiest way to check refill oil in transmission? Triumph 20
AUSMHLY Another transmission oil question Austin Healey 19
66healey oil for transmission Austin Healey 2
dklawson Transmission Gear Oil - Synthetic? Triumph 7
Stewart Leaky transmission oil drain plug MG 3
R Best gear oil for transmission in midget[snail] Spridgets 3
R 1500 with OD transmission oil recommendations Triumph 15
martyc MGB MGB Transmission Oil -- with Tasty Metal Shavings MG 2
ronzet Transmission Oil Recommendations Austin Healey 8
M Transmission Oil Spridgets 13
R Spitfire spitfire transmission and j type O/D oil question Triumph 29
davidk TR6 Transmission Oil Capacity on a non OD TR-6 Triumph 5
B TR2/3/3A tr3 transmission oil fill plug Triumph 18
White79MGB TR2/3/3A TR3 Transmission Oil Triumph 18
ronzet Oil Viscosity Transmission Austin Healey 17
nevets transmission/OD oil question Austin Healey 17
PAUL161 Thanks Doc & Tony -OD & transmission oil change MG 0
T How full to refill transmission oil? Spridgets 4
gbtr6 Transmission Oil/Lube Triumph 4
cdsmith Transmission oil? Rear end oil? Spridgets 15
jsneddon TR2/3/3A TR3 Transmission Oil Capacity Triumph 3
B transmission oil?? MG 10
S TR2/3/3A Tr3 transmission oil Triumph 4
Johnny Transmission oil seals Austin Healey 8
Michael Oritt Transmission oil specification--Toyota box Austin Healey 10
S Transmission oil filler where is it? MG 5
R transmission oil Austin Healey 4
G Transmission oil dilemma Triumph 6
D Transmission oil pump question MG 2
7 Transmission Oil Refil MG 3
T TR2/3/3A Proper oil TR3 Transmission Triumph 3
Steve Transmission oil refill MG 24

Similar threads

Top