I recently put in a replacement 3 speed overdrive in my 58 3/4 ton step van. I connected the speedometer cable to the trans and filled her up with fluid. The speedometer doesn't work and also drips oil from connection point and when I remove the cable. Wondering if I over filled it. I see a bolt next to where the cable screws in and wondering if this is for adjustment? Any suggestions or advice is appreciated.
The "bolt" next to where the cable housing screws in should be retaining a metal tab that keeps the speedo drive "plug" in proper position in your tailshaft housing.
Without knowing exactly which "3 speed overdrive" you used as a replacement, it's hard to determine if you overfilled it or not.
Thinking you need to do a bit to determine what you have, check appropriate shop manuals for type/vintage and check back in with updated info and question.
A picture or two wouldn't hurt either.
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
I took the cable out from the transmission and some oil came out. When it stopped dripping I put a in a drill bit and it went in about 4 inches before it landed on something. There is nothing to turn the cable. This is the same cable I used on my previous Muncie, albeit an earlier model, where it worked fine. I can't look at that one because it's at a transmission shop. Maybe something missing inside or I need a longer cable for the inside?
Thinking at this point we need pictures to help try and figure this out with you.
The cable housing should have threaded on to a "plug" in the large diameter whole in your trans tail shaft housing, retianed by the before mentioned tab and bolt.
That metal plug the cable housing screws onto, holds the output "driven" speedometer gear (plastic) which the inner cable slides into to create a driven connection between there and your speedometer.
As I said, pictures are needed on this end to help figure out what if anything is missing in this equation.
If you need help figuring out how to post pictures, click here: How to Post Images
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
From your picture, it appears externally that everything is where it should be (component wise).
Since the plastic drive gear inside that threaded plug is normally not tight sealed to the plug itself, excessive lube (overfill) can leak out through that space.
Would be a good indicator that your trans is most likely over-filled.
NOTE: The speedometer not working is also a good indicator that there is something amiss with your cable drive assembly. The plastic driven gear could be sheared which would account for no speedo function. Next thing to do will be to pull that speedo drive plug and see what is going on inside.
Let us know what you find please so we can continue to try and help.
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
If the gear inside is missing then it would definitely leak. After removing the retainer, the gear holder can be removed (pulled out) but my memory is that the oil ring makes it a tight fit. I don't recall an internal seal from gear shaft to holder ID but the shaft has a spiral groove.
The parts shown in the picture are examples only. Look up the parts you need.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
I haven't had a chance to remove the gear holder, but certain there is no plastic gear in there. I see there are two different size gears 1961 being the cutoff. Any way of telling what size I need? 2 7/8 is the pre 61 size I've read.
For cars and light trucks you could purchase the 3 speed overdrive option. I cannot verify but I read that 55 to 59 O/D commonly had 4:11 ratio real axle. 59 and up O/D had 3:70 or 3:90. I have no idea what ratio rear axle was used in a 1958 step van.
You didn't say which year O/D you have. Pre-65 4 bolt side cover. 68 up 7 bolt side cover.
The transmission will have an internal steel ring gear that meshes with the plastic/nylon gear as a set. Once you have the gears that mesh, fingers crossed your speedometer reads the correct speed. The speedometer drive gears and your rear axle ratio are variables that you have to figure out yourself.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
Some years ago I swapped out the original differential for a 4:10. I believe the 20 tooth blue gear will be the closest. I can't seem to find much info on stem length however.
You still haven't identified which year transmission you have (read my previous post). SM-319 is the 4 bolt, SM-326 is the 7 bolt You still haven't identified how many teeth are on the gear that meshes with the speedometer drive gear. While inside, do a bit of measurement and get a rough idea on stem length. The vendors who sell these driver gears should be able to tell you the stem length of what they sell. Give then a call.
I'm bowing out on this topic. Please post your solution when you find it. Good luck.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
