On a TT rear axle, there are 3 oil plugs. One is the drain, another is in the center and appears to the upper fill hole and one at the top at the back of the worm drive. Is the top one just the fill hole ?
Yes,it's a filler hole added sometime after production started. It's just easier to get to. The early trucks didn't have the upper hole, but I'm not sure when the change was made.
After reading the question I went out and looked at a couple of rear axles. I don't see any reason for the top hole other than as a filler. I suppose it's up there so filling will bathe the upper works in oil from the git-go, and not depend on the ring gear bringing it up. I assume the middle hole is to achieve the proper oil level. Both kinds of rear axle, regular and Ruxtell, have all three holes.
Thanks. That's what I thought but this is my first TT. Did most of these trucks come with a warford or did more have the. 2 speed rear axle?
It's a complete uneducated guess, but I suspect Ruckstells outnumbered Warfords. I suppose the ideal set-up would be to have both.
My '18 had no filler hole on the upper thrust bearing cover. Axle housing castings also had raised filled or beads where the tubes are fitted. The input splines on the early TT axles are shallower by about 50% also.
Raised "fillets" or beads...
My TT is an early one and the rear end is as you describe, no filler hole on the upper cover, and it has the raised beads on the clam shells.
I didn't know that the axle splines on these early trucks were shallower, I've never had a later one to compare to mine. Interesting. I wonder if the change to deeper splines was made in conjunction with the 1923 change from a differential pinion shaft to a differential spider (along with the necessary changes in the differential gear case).
Since we're talking TT rear ends, there's another matter I'm going to ask about. I've posed this question once or twice on the forum before, but no luck getting an answer.
My TT, I'm reasonably sure, is a 1918. (There are several solid clues to support this conclusion that I can list if anyone is interested.) My question: On each of the rear end clam shell halves, on the top near the thrust bearing cover, there is the number 6315 stamped into the metal. I've never heard that these rear ends were serialized, but apparently mine was. Does anyone know anything about this? To the best of my knowledge the truck was probably assembled in San Francisco, since it was located in Santa Clara when my family acquired it in 1946. Also, at that time the last license plate it carried was a CA 1941, so I'm guessing it did it's first 23 years in or near the Santa Clara Valley.
I don't mean to hijack the thread - But rear ends are rear ends. If anyone has any thoughts on serialized TT rear ends I'd like to hear them. Thanks!
I will check my axle housings for numbers.
I have 5.16 gears, a Jumbo Giant, and a Ruckstell. Having twin sticks is great. You have to work out the gear ratios on paper though if you want to use them all. They don't work out to be in the order you'd think.
Henry, I can't speak for Nick, but I think he was referring to the DRIVESHAFT splines, which WERE changed early on, hence the "input" reference and the "TT axle" reference was for the unit. Just guessing though. I have never heard of different splines on the axle shafts myself. As for the top plug on the housing, I too thought it was a filler. Have any of you tried it that way? I did, and proceeded to procure the correct size Street L and screw it into the middle hole. You could run several errands while trying to fill it up with the top hole. At least, that was my experience. Dave
I think you're right, David. My eyes skipped over the work "input" and read "...splines on the early TT axles...".
Since my TT doesn't have the upper filler hole I've never experience it myself, but I have heard that filling a TT rear end from that upper filler hole can be a long job.
I just put my TT's rear end back in today. Still have to put on the rocky mountains and hook everything back up. But I am feeling pretty good finally getting it back on the truck. Still lot's to do, but I hope to have it on the road this year. It now has high speed gears and a Rocky Mountain six speed under - overdrive :-)
With regard to having a Warford and a Ruckstell in a TT...it is a good combination....along with a high speed rear end ratio. I have been running such for 40 years.
one of these days, we should try to have a TT gathering here in Cali :-)
That Fill Hole Has A Reason
Wow, I thought for sure that someone else would have known what the filler on the Thrust bearing was for.
This is what the upper plug is for. Ford had some issues with the thrust bearings on the TT's trying to burn through the bearing cover so they did two things. First they must have though that this was do to inadequate lubrication so a plug was used to prefill this thrust for initial start up. Second, shortly after this the cover was hardened by Ford to challenge the wear on the cover. Some of this info can be found in the Service bulletins.
It is advisable in my opinion to put a few ounces of your 90w 140 gear oil in this upper plug if the differential has been sitting for a while. This bearing will go dry from sitting and it takes some time before oil can get back up in there by just driving your truck.
No this is not a filler hole but used just to prelube the thrust bearing before it can get its oil supply from below. If you have ever tried to fill the differential you know it could take days to fill it this way.
That makes sense Fred. Thanks for the update. Dave
Kim: Here is one answer to your Warford vs Ruckstell question. I have some ledgers from a Ford Dealer in Bell TN. In the sales where there was a Ruckstell sold with a truck, no labor charge. There was a $6.00 labor charge for installing a Jumbo. Also, a TT Ruckstell was $78.90 and a Jumbo was 125.00. There were more TT Ruckstell than others. Dan.
In addition to what you posted it would be interesting to know what rear end gears the trucks that got a Ruckstell had. Obviously, we all know that a stock TT has two speeds, slow and slower. A Ruckstell would offer an even slower option that makes a little more sense to me if the rear end has a high ratio set of gears.