Model B Transmission

As for the lube... Lots of guys use 80-90 GL5. Some guys say GL5 eats up the bronze bushings though. I don't really know. I used to use it BUT, after reading some specs (from the API), I convinced myself to switch. Since I have a touch of CRS, I could be wrong on this but I think I switched to MT1. It's for extreme pressure, high shear, straight cut spur and worm transmissions. Had to go to a petroleum distributor & order it though. I do use heavier weights. I don't use my tractors for much heavy work in the winter so I'm not so concerned with the lighter weights for winter use. I kinda look at it like today's 90-120 or 90-140 MT1 is a LOT better lube than the 140 mineral oil they were designed to be cooled and lubed with over a half century ago! My 70D seems to be happy with the MT1. Hasn't ate any holes in the sump..... at least not yet!

If you're only going to use it for light service, I'd think either one will do well. Some guys advocate using motor oil instead of gear lubes. There's been a lot of discussion on gear lube for in the past. You might try looking in the archives or just ask again. Been a while since there was much gear lube discussion.

Takes about 8 gallons of whatever.

You mention that you had the cover off of the transmission. For that reason I suspect your had the transmission in the low range but the gearshift in the high range when you replaced the cover. For that reason I'd do the following.

Remove the cover. Inspect all of the detents, the shifter shafts (not bent), the forks (none broken or cracked) and make sure that the shifter gates can all be lined up.

You'll see 4 shifting forks. The 'odd one" (looks very different from the other three) is the hi/lo range shifter. It has a single "high level" gate while all others are double gate shifters with their gates at a lower level or "deeper in the transmission". The forward most of the lower three is the 1/3 Reverse shifter. This is the only shifter that has three detents. Make sure it is in neutral which is the center position. The next back would be the 2/5 shifter and the rear most shifter is the 4/6 shifter. Push these last two shifters to the left detent. All of the gates of the lower three shifters should now line up and your belt pulley should turn freely because the transmission should now be in neutral. If they don't line up smoothly, then the positions of the shifter shafts would need to be adjusted. That would best be another post and we'll assume they line up for now.

To reassemble, I find it easiest if I first place a late model B in 4th gear. To do so, slide the range shifter (the odd one) to it's left position which is the low range. Slide the rear most shifter (4/6) to the right or "in gear" position. The other 2 shifters MUST remain in their neutral positions. Place the gearshift (the handle proper) in the 4th gear slot of the shifter quadrant and block it there with a block of wood. When a late B is in 4th gear the gear shift is very nearly perfectly vertical. With everything set in this manner, the entire quadrant assembly, cover, steering pedestal and gearshift can be lowered straight down positioning the lower ball of the gearshift in the 4th gear (left) gate of the 4/6 shifter.

Loosley install the cap screws and "run the shift pattern". Remember you may have to turn the pulley occasionally to get gears to line up. If it shifts properly into each gate, tighten the cap screws. If it does not shift properly, then the shifter shaft positions may need to be adjusted but try all this first.

Let us know what you find.

Later!

I am a little confused. My tractor is a 1948 B and it doesn't have a hi-lo range selector (I don't think), it just has a six speed shift geer gate. I don't think the set up you are referring to was still available in 1948. It sounds to me like he can only go through the gears on the left side of his shifting pattern. Maybe I am misinterpreting his post or yours (or both!). I will keep my eyes open to see how this goes. Gary

Even though the late model tractors had a single gear shift lever, they still were a three speed transmission with a HI LO that gave them their six speeds. On the late B's, gears 1, 2, 4 and reverse were on the LO side. When you drop the gear shift lever to the crossover slot from the LO to HI sides of the quadrant you are shifting the range shifter. When you slide the gear shift into 3rd (or 5th or 6th on the HI side) you actually are sliding and shifting the EXACT SAME gears on the sliding gear shaft as you did when you slid the lever into the 1st, 2nd or 4th gear gates! Basically it's the same as the two gear shift transmissions but the engineers designed some operator convenience into the transmission by making a single lever do all the work! The single gear shift design and quadrant also prevents operators from putting the tractor into the high reverse, something that "could" be done with the 2 shifter design. Lo reverse was plenty fast. The HI reverse is a white knuckle ride! A mid series A in HI range reverse will come real close to out running an H in high gear full speed ahead! They built interlocks into them to prevent this but interlocks can be "worked around".

Hope this helps clear things up a bit.

Later.

I was wondering if it wasn't something like that, because of the wierd shifting pattern. Thanks for clearing it up. I(I know what you mean about the high speed reverse in these tractors! It takes a delicate touch to back these dragons up to an implement. I bet 90 per cent of the clutch wear happened while backing up to something!)
Thanks again for your information and patience.
gary