Transmission Leak: Can it wait until next winter?

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toofless
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Transmission Leak: Can it wait until next winter?

Post by toofless » Fri Mar 29, 2019 10:48 pm

Hi everyone,

I just got SRL10160 back on the road after finishing a bunch of work in the engine bay. The transmission wasn't touched during that effort. I've got probably 150 break-in miles on the clock now and I have a consistent transmission leak coming from the clutch boot area similar to what was recently reported in this thread. I may try replacing the seal with the transmission in place as is detailed by @mraitch in that thread but I've also got a 1st & 2nd gear synchro issue to address at some point, so it's gotta come out eventually. I just don't want to do it right after 9 months of rebuilding the motor and replacing basically everything in the engine bay...I want to drive this thing!!

After a couple of ~30-mile jaunts, the leak has been maybe 2-3 tablespoons each time. The seals on both sides of the driveshaft are leaking as well, but they're not dripping so I'm not too concerned. I will replace both the transmission and the differential oil before I get this thing back down on the ground. There's more than 2 quarts of fluid in the transmission so I plan to monitor the situation and top it off as necessary. Aside from the leak, the clutch isn't slipping and I don't have any issues other than some grinding when downshifting to both 2nd and 1st (which can be avoided by just being real slow with those downshifts...double-clutching works too but I'm lazy!).

My question is whether this somewhat-undiagnosed issue is OK to keep nurturing until the winter when I can pull the transmission for some other work? If so and given that it doesn't start to leak more, would you feel comfortable taking it on a 500-600 roadtrip if it was topped off before you left?

Many thanks for any insight you might have!

Oh, and just for clarity, it's coming from the area indicated below - this picture taken after I'd already wiped down the bell housing and other parts:
SRLTransmissionLeak.jpg
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mraitch
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Re: Transmission Leak: Can it wait until next winter?

Post by mraitch » Sat Mar 30, 2019 12:06 am

leaks can be from the engine or the transmission. Engine oil and gearbox oil taste (?) and smell differently. Suggest getting tranny hot, draining all oil and refill so you have a starting point. And then you might identify where the leak is coming from.

Than just keep all at appropriate levels until you decide to pull engine to solve problem.

And learn to double clutch - i do it automatically, and rev between each upshift.
Peter Harrison
1970 1600 (Stroker) - TOAD SAN (Eliza)
1970 1600 (Stock) - As Yet Unnamed
Lake Balboa (SFV) , California

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Re: Transmission Leak: Can it wait until next winter?

Post by C.Costine » Sat Mar 30, 2019 7:19 am

mraitch wrote:
Sat Mar 30, 2019 12:06 am
leaks can be from the engine or the transmission. Engine oil and gearbox oil taste (?) and smell differently. Suggest getting tranny hot, draining all oil and refill so you have a starting point. And then you might identify where the leak is coming from.

Than just keep all at appropriate levels until you decide to pull engine to solve problem.

And learn to double clutch - i do it automatically, and rev between each upshift.
Mraitch, revving between cluchings on an up shift is counterproductive and hard on your synchros. The whole idea is to make the two ends of the transmission match up speeds of rotation. The backend will stay close to the same because it is attached to the rear wheels, while during an up shift the front of the transmission needs to slow a lot due to the higher ratio. This becomes very apparent while shifting a heavy truck which has no synchros, which most drivers do without clutching at all. Of course we don't want to be shifting our roadsters without the clutch as this is hard on the synchros. As for telling whether the oil is from the engine or the transmission is easy, once the engine oil has a few miles on it. The engine oil is black and transmission oil stays yellow.

toofless, given that you have 64 ounces of oil, and that you can probably stand to get down to half of that before it stops splashing, and you are losing around an ounce per ten miles, you should be able to drive approx 300 miles. You would want to keeping mind that the leak will most likely worsen. With some plumbing fittings and some vinyl tubing you could move your fill point up through your shifter opening and refill during the course of a long drive. Or you could plumb into a five gallon bucket in the trunk and mount a plunger pump beside your parking brake and replenish on the go, LOL.
located in Chester NH
1967 1600 in restoration
2013 Arctic Cat F-1100 turbo
Ford F-350 6.0
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toofless
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Re: Transmission Leak: Can it wait until next winter?

Post by toofless » Sat Mar 30, 2019 10:32 am

Thanks y'all. The reason I believe it's the transmission is that, contrary to how the leaking fluid should look, the stuff coming from the transmission is really dark and it was clearly coming from the clutch boot area of the bell housing before I cleaned everything up; it must be super-duper old? The motor just went through a complete rebuild less than 200 miles ago and its oil looks like you'd expect after an oil change...and, there's nothing remotely close to that color hitting the floor.

The color is consistent with that (really dark) at the backside of the transmission where it meets the driveshaft but definitely more yellow where the driveshaft meets the diff. But again those aren't dripping so they're less of a concern.

@C.Costine - interesting idea the plumbing through the shifter - I will definitely give that some more thought if/when I plan any long drives or if it gets tiresome getting this thing up in the air!
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Gregs672000
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Re: Transmission Leak: Can it wait until next winter?

Post by Gregs672000 » Sat Mar 30, 2019 12:58 pm

Forgive me, off topic but mentioned here... I'm not sure how rev matching could possibly be harder on syncros and counterproductive? With my aluminum flywheel the rpms can drop quickly between shifts, so I blip the throttle and literally drop it into gear in a fully smooth transition. I have prided myself on being good to my trans and clutch, and evidence of that has been multple cars ive owned where the clutch has way outlasted expected use (for example, i just sold my 2000 Celica that i bought with 56k on the clock and sold with 237k on the original clutch with no signs of problems or slipping. Same with my '83 Celica, only that one had over 325k on the original clutch, purchased with 80k on it). I noted I could and have shifted gears without the clutch so I get the idea of matching rotating speeds, and I thought that this was what the syncros were there for... to match things up smoothly for the next gear, NO? Educate me!
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'67 2000 #588
Tacoma, WA

toofless
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Help Confirming Servo Type Transmission

Post by toofless » Sat Mar 30, 2019 5:00 pm

I got the transmission drained - the really dark color of the leaking fluid is due to some real sludge that's built up in the bottom of the case. I have SRL10160 and I have found documentation that the Borg Warner transmission didn't start until SRL11757.

Endoscope to the rescue: not being a transmission specialist can someone please confirm that I'm looking at a Servo Type synchro ring here? I don't see any brass and the sleeve past the teeth looks like the Servo-type I have seen in other pictures. I'm 99.something% sure but I just want to make sure that GL-5 spec is the fluid that I need when refilling this guy.

Thanks!
SRLSync1.jpg
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- '69 SRL
- '08 Triumph Tiger 1050
- '10 Panamera

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Re: Transmission Leak: Can it wait until next winter?

Post by david premo » Sat Mar 30, 2019 5:24 pm

Yes that is a servo box.

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mraitch
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Re: Transmission Leak: Can it wait until next winter?

Post by mraitch » Sat Mar 30, 2019 7:39 pm

servo vs borgwarner - differences?? which is better??
Peter Harrison
1970 1600 (Stroker) - TOAD SAN (Eliza)
1970 1600 (Stock) - As Yet Unnamed
Lake Balboa (SFV) , California

toofless
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Re: Transmission Leak: Can it wait until next winter?

Post by toofless » Sat Mar 30, 2019 8:40 pm

Thanks David!

mraitch, I don't know of the differences except for the brass vs. steel synchro rings: you need different spec fluid (GL-4) for the brass in the Borg Warner transmissions because the GL-5 spec will corrode them over time...at least that's my understanding from researching several threads on this board. I can't speak to which is better but the Borg Warners didn't start until late and I reckon they usually don't change something mid-production because it's inferior to the existing part.

I found reference to timing of the change on one of the vendor sites, Rallye Enterprises, here where it also mentions the inconsistency in external markings and the idea to use "a mini camera with an LED light" (i.e. cheap endoscope) which is how I determined which version I have. Others on this forum have noted that you can't rely on VIN or other indicators alone, given unknown swaps.
- '69 SRL
- '08 Triumph Tiger 1050
- '10 Panamera

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Re: Transmission Leak: Can it wait until next winter?

Post by C.Costine » Sat Mar 30, 2019 8:59 pm

Gregs672000 wrote:
Sat Mar 30, 2019 12:58 pm
Forgive me, off topic but mentioned here... I'm not sure how rev matching could possibly be harder on syncros and counterproductive? With my aluminum flywheel the rpms can drop quickly between shifts, so I blip the throttle and literally drop it into gear in a fully smooth transition. I have prided myself on being good to my trans and clutch, and evidence of that has been multple cars ive owned where the clutch has way outlasted expected use (for example, i just sold my 2000 Celica that i bought with 56k on the clock and sold with 237k on the original clutch with no signs of problems or slipping. Same with my '83 Celica, only that one had over 325k on the original clutch, purchased with 80k on it). I noted I could and have shifted gears without the clutch so I get the idea of matching rotating speeds, and I thought that this was what the syncros were there for... to match things up smoothly for the next gear, NO? Educate me!
Greg, rev matching is what I was talking about. We know that the engine will turn at a lower rpm in a higher gear given the same ground speed, right? so when shifting up the engine needs to slow down in order to match. Aluminum flywheel or not, blipping the throttle doesn't help the engine RPMs to drop.
located in Chester NH
1967 1600 in restoration
2013 Arctic Cat F-1100 turbo
Ford F-350 6.0
Ford 9000 puller, Ford 960 puller, Ford 901show, Ford 971 worker, Oliver 70 waiting its turn

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Re: Transmission Leak: Can it wait until next winter?

Post by JT68 » Sun Mar 31, 2019 7:45 am

toofless wrote:
Fri Mar 29, 2019 10:48 pm
I have a consistent transmission leak coming from the clutch boot area similar to what was recently reported in this thread. I may try replacing the seal with the transmission in place

Realistically, I don't think you will have success changing the engine rear main or transmission input seal with the engine in place. You could change the rear main cap side seals, but I doubt that is your leak, and its a lot of effort.

The fit of the engine rear main/rope seal is extremely tight, so you won't pull it in place with fishing line or anything like that. Don't waste your effort. You won't even get the old one out without removing the crankshaft.

The transmission input shaft seal cannot be changed in place. That's simply impossible.

Are you sure the leak isn't coming from higher up and running down inside the bell housing? Valve cover?, head? even the tach seal? Those could contribute motor oil, but not 90W. If definitely 90W, you would have to pull the Engine &trans.

Probably not what you want to hear, but its roadster reality.

To answer your original question, if its just a few teaspoons 90W, yes it can probably wait- if its a cup every time you drive it, probably not. j
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Re: Transmission Leak: Can it wait until next winter?

Post by toofless » Sun Mar 31, 2019 9:01 am

Thanks for saving me the effort, JT. I'll do another inspection above the bell housing - good thought. I still don't see how it could be so dark, though, given the brand-new engine oil. The color was consistent with the color of the transmission fluid that I drained last night and while I haven't measured how much came out of the drain plug, I don't think it was near the 2+ quarts that's supposed to be in that thing.

Had I better sense I would have just taken the entire transmission to get a good inspection while the motor was out for 4+ months. Hopefully it doesn't get much worse over this season.
- '69 SRL
- '08 Triumph Tiger 1050
- '10 Panamera

"You never get what you don't ask for..."

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Gregs672000
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Re: Transmission Leak: Can it wait until next winter?

Post by Gregs672000 » Sun Mar 31, 2019 11:19 am

C.Costine wrote:
Sat Mar 30, 2019 8:59 pm
Gregs672000 wrote:
Sat Mar 30, 2019 12:58 pm
Forgive me, off topic but mentioned here... I'm not sure how rev matching could possibly be harder on syncros and counterproductive? With my aluminum flywheel the rpms can drop quickly between shifts, so I blip the throttle and literally drop it into gear in a fully smooth transition. I have prided myself on being good to my trans and clutch, and evidence of that has been multple cars ive owned where the clutch has way outlasted expected use (for example, i just sold my 2000 Celica that i bought with 56k on the clock and sold with 237k on the original clutch with no signs of problems or slipping. Same with my '83 Celica, only that one had over 325k on the original clutch, purchased with 80k on it). I noted I could and have shifted gears without the clutch so I get the idea of matching rotating speeds, and I thought that this was what the syncros were there for... to match things up smoothly for the next gear, NO? Educate me!
Greg, rev matching is what I was talking about. We know that the engine will turn at a lower rpm in a higher gear given the same ground speed, right? so when shifting up the engine needs to slow down in order to match. Aluminum flywheel or not, blipping the throttle doesn't help the engine RPMs to drop.
Ok... what I do is rev the engine to match what the rpm will be when I drop it into the next gear because the rpms drop below that unless I'm shifting really quickly. Otherwise you can get a lurch because the engine drops rpm so fast that it's having to catch up to the trans (vise versa for a down shift). For my clutch, I imagine that's more wear on the disc as it slips between the two... less rpm difference the less the disc has to slip. Or is my "vision" incorrect? :D

Again, sorry for the thread hack. Let's see, I can contribute by saying I love Swepco gear oil! When you get it all sorted out, that's the gear oil I would use! Trans temps dropped considerably.
Greg Burrows
'67 2000 #588
Tacoma, WA

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Re: Transmission Leak: Can it wait until next winter?

Post by JT68 » Sun Mar 31, 2019 11:36 am

toofless wrote:
Sun Mar 31, 2019 9:01 am
Thanks for saving me the effort, JT. I'll do another inspection above the bell housing - good thought. I still don't see how it could be so dark, though, given the brand-new engine oil. The color was consistent with the color of the transmission fluid that I drained last night and while I haven't measured how much came out of the drain plug, I don't think it was near the 2+ quarts that's supposed to be in that thing.

Had I better sense I would have just taken the entire transmission to get a good inspection while the motor was out for 4+ months. Hopefully it doesn't get much worse over this season.

As Peter pointed out, you (I) can usually tell from the smell/color/thickness. Dino 90wt has that putrid smell to it that motor oil doesn't. If using synthetics, the color and or smell is still usually different from motor oil (depending on what you are using). Best, J
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Re: Transmission Leak: Can it wait until next winter?

Post by C.Costine » Sun Mar 31, 2019 1:16 pm

Gregs672000 wrote:
Sun Mar 31, 2019 11:19 am
C.Costine wrote:
Sat Mar 30, 2019 8:59 pm
Gregs672000 wrote:
Sat Mar 30, 2019 12:58 pm
Forgive me, off topic but mentioned here... I'm not sure how rev matching could possibly be harder on syncros and counterproductive? With my aluminum flywheel the rpms can drop quickly between shifts, so I blip the throttle and literally drop it into gear in a fully smooth transition. I have prided myself on being good to my trans and clutch, and evidence of that has been multple cars ive owned where the clutch has way outlasted expected use (for example, i just sold my 2000 Celica that i bought with 56k on the clock and sold with 237k on the original clutch with no signs of problems or slipping. Same with my '83 Celica, only that one had over 325k on the original clutch, purchased with 80k on it). I noted I could and have shifted gears without the clutch so I get the idea of matching rotating speeds, and I thought that this was what the syncros were there for... to match things up smoothly for the next gear, NO? Educate me!
Greg, rev matching is what I was talking about. We know that the engine will turn at a lower rpm in a higher gear given the same ground speed, right? so when shifting up the engine needs to slow down in order to match. Aluminum flywheel or not, blipping the throttle doesn't help the engine RPMs to drop.
Ok... what I do is rev the engine to match what the rpm will be when I drop it into the next gear because the rpms drop below that unless I'm shifting really quickly. Otherwise you can get a lurch because the engine drops rpm so fast that it's having to catch up to the trans (vise versa for a down shift). For my clutch, I imagine that's more wear on the disc as it slips between the two... less rpm difference the less the disc has to slip. Or is my "vision" incorrect? :D

Again, sorry for the thread hack. Let's see, I can contribute by saying I love Swepco gear oil! When you get it all sorted out, that's the gear oil I would use! Trans temps dropped considerably.
OK, I can see that if you are shifting in a slow relaxed manor that the RPMs could drop below the mesh speed. Many drivers of big trucks will engage their engine brake to bring the RPMs down to matching speed more quickly, so as to not lose their hard earned momentum as they shift up.


On the transmission, you have a temp read-out on it? I assume that it is electronic. Where did you get it?
located in Chester NH
1967 1600 in restoration
2013 Arctic Cat F-1100 turbo
Ford F-350 6.0
Ford 9000 puller, Ford 960 puller, Ford 901show, Ford 971 worker, Oliver 70 waiting its turn