Ok, So here is a simple question that I need a simple answer to. What is the quickest way to tell a regular TT ring and pinion from a "high speed set". The number of teeth, markings, etc? Keep in mind these will be out of the rear end and taken apart when I am looking at them. Thanks in advance, Paul
look at page 52 in the 8-5-28 parts book. You can count the teeth of the two different gear sets.
Paul. The high speed worm will have 6 teeth the bronze gear will have 31 teeth. The low speed worm has 4 teeth and the bronze has 29.
Another question about those gears, Iam looking for a set. But I have been advised by those that know alot more about TT's or T's to not even bother as they were all worn out 30 years ago, their all shot. How worn out is too worn out?
Not looking to have a work truck, just weekend fun drives and no real loads. Any advice what to look for? besides I would think busted or chipped teath, what do you guys think? Tom.
Good question. I have 4 sets, one is in my truck.
The worst set I have came out of a homemade tractor.
There are some other fellows on this form with high speed gears, maybe they will jump in and give some of their thoughts on the subject.
Here is a link to a set on ebay, but the brass ring looks well used.
I bought a rear end with the high speed gears which I haven't looked inside of but judging by backlash in the worm shaft I don't think they're worn out. I also believe you can turn the worm gear around when you install it so that the worm will be pulling on fresh teeth as you travel forward. Of course, this wouldn't help much if the teeth are too far gone. I also believe that about 20% STP added to the oil will prolong the life of a worm-drive gearbox. Where I worked we tested this theory on a worm-drive that was in 24/7 operation and running at about 240 degrees. After adding the STP the temperature came down to 185. I don't remember the gearbox's history after that but it seems lower temperature means less friction. Now, you wouldn't want to let any of that stuff get into your transmission as I think that would cause trouble with the bands. Bob
I'm the guy with the gears on ebay. I'll be adding better photos this evening.
I just hope I don't kick myself later for even selling them.
New question related to this thread:
To determine the rear end ratio in a TT (7:1 or 5:1 approx.), you can turn the drive shaft (engine is out) and count the revolutions vs. what you see on the wheels.
I turn my drive shaft 1 revolution and the wheels turn about 3 and 1/4th turn... so:
How many times should I turn the shaft to create an accurate estimation, and what is the formula? A friend, when I told him what I found, calculated it to be 5:1. I hope he is right..
I thought of another piece of information that would be realy handy for us guys looking for high speed gears. How about a pair of photos of a good TT ring gear and a bad one. Anbody have any pics? Thanks Paul
Michael, due to the nature of a differential both rear axles have to rotate an equal number of turns or an average thereof. To determine the ratio let one axle be free to turn and the other held stationary. Rotate the pinion (worm) shaft untill the one axle makes exactly two turns. One axle two turns, other axle zero turns, averages one turn each. The number of turns the pinion makes to accomplish this is the ratio. If the axle is in a vehicle jack up one rear wheel, remove the spark plugs if you wish, set the transmission in high, auxillary transmission (if any) in direct, Ruckstell (if any) in high. Crank the engine over untill the one wheel makes two turns. Number of turns of the engine is the ratio. A TT truck should be 7 !/4:1 (low speed) or 5 1/6:1 (high speed). Hope this helps. Bob
You beat me to it Robert.
I wonder if he only had one wheel turning when he estimated the 3-1/4 turns? A 7.25:1 ratio would be 3-1/8 turns of the drive shaft for one turn of the wheel if the other were not turning. That's real close to 3-1/4......
They were both turning.. it is up on blocks. It was one turn of the drive to 3 1/4 turns of the wheel...
When I put the wheels back on I will check Robert"s method..
Thanks everyone... One of the reasons I want to know is that I am thinking of putting in a Warford transmission... But if it is the low ratio I am not sure it would be worth it.. no matter what it will be slow. With the 5:1 a warford might make a difference and push me to 35 anyway..
I have a TT truck that i think must have the high speed rear end in it because when i had it running good, full throttle i was able to get about 32 MPH out of it.
Nobody has any pics of a good and bad TT ring gear??????
HI, I have the high speed gears in my TT They are worm gears unlike the ring and pinion as in the cars. The contact area is far greater and spread out. So gears that dont look to good will work just fine. My gears looked bad and have been in over ten years. I put heavy loads on this poor old truck and travel up to 85oo feet in the mountains and down to the valley floor. Do the math and you will see that with 650 - 20 tires and 1750 rpm you will be about 40 mph. I used a gps and it showed 42 flat out empty on flat ground. The worm gear is brass so you need to use the right oil. And the worm gear makes no noise, so far. I love my 5.17 gears. See ya in the hills, Scott
Way to go Scott, thanks for that info. That seems to be what Iam hearing from guys with them in their trucks. Did'nt want to throw money away on a set I could not use.
The set on t-bay went for $356.55.
If I aint bad mistaken Ray Elkins brought up the question if a early 28 AA wormdrive's gears would be the same and if so,would they be a higher ratio than standard TT?
I cant remember the answer to that.
I do know I am kicking myself for giveing away a AA wormdrive about 5 years ago.It went to a fellow with a truck that needed it though.
Is anyone makeing these high speed gears?
Someone said use the right oil in the rear end.
I use the 600 wieght.I hope that is ok.
I have a TT that I built up in 1974 and ran national tours until 1996. It has high speed gears in the Ruckstell and a Jumbo Giant overdrive. Last simmer I ran 42 MPH on the Wendchester Speedway at the centennial. I use 90-140 with 1/2 can of STP in the rear end. I have run the Newport HILL Climb for 35 years. Havn't had any problems.
I use 140wt Mobil, rear end 80w90 mobil, aux trans. Chaffin's parts man said GL rating of at least 5. Mobil 140 has 7
I belive that yellow gears need mineral oil. Cars have steel gears but the TT,s have worm gears of brass and pinion gears of steel. so run what you want but the worm will hold up better with mineral oil. Scott
Would you post a couple pic's of your TT?
How long were some of the national tours, you drove with the TT?
Whoever won the bid on the high speed gears is will not be sorry. IMHO they make a TT alot more fun to drive.
I won the bid, hope your right Rod. I did'nt want to spend that much - but my TT is just to slow to even drive around LA. With the traffic we have, 15 mph is just to slow. So we will see, hopefully in a couple months I will have it up and running with the high speed gears and a Rocky Mountain three speed. You guys comments made me go for it, having good luck with the old gears, thanks. I drive everything I have easy so Iam hopeful they will hold up. Just one more reason I like this forum !
Watch for an email offline
Congrats on getting the gears. I believe the high ratio gears with the 3 speed in high will produce upwards of 45 MPH. Do you have aux brakes? I'm not familiar with the RM 3 speed, but it's possible with my Muncie to get stuck between gears, so without aux. brakes you could wind up with a pretty thrilling ride very suddenly.
Ya know how it is, one thing leads to another....
Thanks Henry, I will have to look into that. I thought my truck had Rocky mountain brakes, just looked big to me - not knowing. But their just the stock brakes. As you say, my truck needs alot of attention and thats just the stuff I know of, I am sure there lots more to come. I will e mail you thanks Rod, Tom.
Rod, I don't have any way to post a picture on here but it has been on the cover of the Vintage Ford 2 times. Sept-Oct 1976 Nov-Dec 1987 Bruce