VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 Oil Leak at Speedometer, 1930

Had my '31 Coach ('30 motor/tranny) for a drive for first time last week after 4 years of work. Notice this week that oil is seeping from sheathing of speedometer cable near where it attaches to U-Joint case. Could not find the speedometer in 29-32 parts book in the obvious places (Tranny section, instrument cluster etc) so don't know what I'm facing if I decide to unscrew the knurled part. What stops this from leaking oil. Is there a gasket, possibly worn bushing? I have 600W in this U-Joint case. If bushing is worn, does someone sell one?

Unfortunately, a leaking speedo cable is fairly common:

https://vccachat.org/ubbthreads.php/topics/204524/1

https://vccachat.org/ubbthreads.php/ubb/showflat/Number/182864/Searchpage/1/Main/29492/Words/%22Speedometer+cable%22/Search/true/Transmission_leak#Post182864

https://vccachat.org/ubbthreads.php/topics/129059/1

https://vccachat.org/ubbthreads.php/ubb/showflat/Number/118523/Searchpage/1/Main/19019/Words/%22Speedometer+cable%22/Search/true/Re_Speedo_cable_to_u_joint_hou#Post118523

Mine leaks too, but I just put up with it. If it stops leaking, then I know I'm about out of transmission oil. (This method also works for the fluids in my Land Rover.)
Looks like you'll have to cut and paste two of the links.

Happy Motoring,

Dan

There are several post on this issue. Unscrew the nut and pull the cable end out. If there is no felt washer around the drive pin fabricate one and slip it over the pin and re-install. Also where the cable attaches is a nut that holds in the speed driven gear which should have a groove cut in it to allow the oil to return to the trans. Be sure the groove is not plugged or worn away.Good luck.

Speedometer cables are not listed in the 1929-32 parts book.

Mine leaks too. I just wrap Tin Foil around it and thats the end of drips on the floor. Al W.

Mine leaked from a small split in the cable where it rubbed on the brake rod. I put a length of heater hose over the damaged area with a clamp on each end. No more leaks.

A small felt seal on the inside of the cable where it connects to the universal joint retainer will do the same thing and it won't be visible.

Thanks DanR and others, have read the noted previous threads and will disassemble tomorrow and see what I am dealing with. I'd be satisfied with a few drops a week, but have much more than that at the moment, probably 1/2 cup in a week, just sitting in garage. As for the Speedometer and cable not being listed in the 29-32 parts price list, at least I'm not losing it!

If you are getting 1/2 cup per week out of your speedometer cable you might have too much oil in your universal joint retainer.

Morning Dawg. Hope you've been out for your walk.

As for the U-Joint case, after draining it 2 weeks ago(there was not more than a couple of teaspoons of black gunk)I measured carefully the 8oz. you and others suggested, and at 7oz. it was full at top plug location. Though that may have been more than necessary, you did say no more than 8 oz. When I refill this week, may go for a lower level, perhaps 5 oz,and see how that works. No one seems to say what level is proper, and I assume the filler plug is intended for just that, i.e. to fill it. May try to match level of oil in tranny.

Yep, just got back from my walk and I checked out all of the fire hydrants and the trees.

If 7 ounces is filling your universal joint retainer up to the top pipe plug there is too much oil in the retainer. At that level the oil would also have to fill up the universal joint ball back to the torque tube seal behind the torque tube bushing. Ideally, you only want to cover the speedometer driven gear in oil. Also, if you have an open bearing in the back of the transmission some of the transmission oil is going to filter through the bearing and into the universal joint ball retainer as well.

Glad you got your exercise. Took speedo connection apart this am. Virtually all 7 oz of 600W oil had leaked out by now (about 10 days). I note in the parts book the speedo drive assembly (pg22) includes a bushing and a spacer. When I removed the sleeve for the driven gear(#590106), there is no sign of a spacer (#354756) or bushing (#590413) on this outer end. The drive shaft is 5/16"dia and the sleeve is 3/8" inner dia, suggesting a bushing or spacer may be missing? Finally, if a felt washer of some sort is to be installed, I assume the intent is to pack the inner cone of the flared end as snug to the cable as possible without interfering with the flare's ability to make a tight joint to the sleeve? It appears the oil is passing everything and going into the cable sheath and then seeping out, although it may be seeping past the the flared part where it is "squeezed" onto the sheath. Any more advice, especially regarding a spacer/bushing missing and where one may find one?

I have checked further. Removed the speedo end bearing nut, and it measures inside dia 0.3145". Speedo drive shaft is 0.3090 dia, leaving a dia difference of 0.0055" or about .0027" clearance, lets say about 2-2.5 thou, allowing for some wear. The outer sleeve bolt has an inner diameter of 0.3740, thus a difference of .075, or 37 thou. so this must be where the bushing goes. Spoke to my local engine fit shop and they suggest pressing a valve guide into the sleeve and boring to leave about 2 thou clearance.
Then there is the question about the "spacer" mentioned in the parts book. I do not see any sign of one, and assume it was slipped over the shaft and situated between the sleeve bolt and the gear on the shaft to minimize the shaft from moving excessively. I realize the speedo cable is spring loaded and keeps the shaft generally snug against the end bearing. I'm figuring this out by process of elimination so let me know if I'm off the mark. If I am right, those of you who have leaky speedo cables may want to pull the sleeve bolt out, check if bushing is worn, and if so, get a new one put in. At 2 thou clearance, 600W should not leak when standing, perhaps a drop now and then when flying down the road at 60 MPH!

Update: Took whole speedo drive assembly out. Everything is there except the bushing for the sleeve nut. The spacer sits as a loose fit onto shaft between the drive gear and the inside of the U Joint case casting, stopping the shaft from moving laterally. Have taken the assembly to the Engine Repair shop (Nova Automotive, the best locally), and they will make a proper bushing and press in sleeve bolt. I think they plan to use a bronze valve stem guide to start with. Will likely fit to about 2 thou, should prevent leakage when standing, may still allow a small amount to pass on the road. As for the groove in the end of the driven shaft, it is primarily for the small fin on the cable to key into to enable cable to rotate as shaft rotates. Don't think it will assist oil to return to case since it is fully enclosed in the bushing. Also, the oil level in the case is higher than the bushing so if anything, tendency is for the oil to seep out. As for a felt gasket, will leave that as a last resort, assuming the new bushing if made with proper clearance should solve the problem. Cheers.

The groove on the outer part of the shaft of the drive gear is spiral. The internal spline is what I believe you are referring to for driving the cable. Perhaps the 30 is different than my 32. The external spiral groove is reverse cut to the direction of rotation and will force the oil between the shaft and bushing back into the case. If you have doubts about how this works try putting a screw on a reversible drill and put it in a cup of oil and try it in both directions. If your gear/shaft has no groove and is submersed in oil all the time I don't know what will keep it sealed.

Not sure if my speedo gear is 1930 or 1931, but in any case it has no spiral groove. The end of the shaft has a slit one side only, going the depth of the hole in the shaft required to receive end of cable. Parts book lists same shaft for 29-1931, but a different one for '32. So perhaps the spiral groove you mention began then.

I had a leak in my 1930 Speedo Cable sheath and i worked a small amount of High Temperature Black Silastic ( Permatex ) between the outside of the sheath and the cable housing at the end of the cable (just before the nut where it fits into the transmission ).

It fixed the problem no more leaks .

Regards,

Paul

Have finished this little annoyance, see photo essay at left. On to the next job!

Possibly there is a misprint in your '30 owners manual or they changed it for that year but for reference my '29 manual says 4 oz in the universal joint housing.

Thanks for that info. I may drain off a couple of ounces, don't want this stuff running down torque tube.