Gear Oil - '39 top loader
- Thread starter Ryan
- Start date
MattStrube
Member
Last year: some nasty red **** I got from speedway, it's for rear ends. Now I use some carquest brand i just picked up 90w, but i have the same issue you do...grinding into 2nd.
Last edited:
GreenMonster48
Well-known member
is 85W-90 comprable to 90W? My local Napa doesn't seem to carry straight 90 and the stuff that's sitting in my gear box is going to turn back into a dinosaur any day now.
Joe KCMO
Senior Member
For what it is worth, the first number (85W) tells you the actual viscosity rating. The second number tells you the viscosity level which the oil performs to. I just wonder with these old cars and the tolerances they were built too, that we should use what was originally asked for. New engines with very small tolerances need low viscosity oil. For example, I have seen 0w,40. I would not believe that this would be good for my old ford. Just sayin.
Last edited:
GreenMonster48
Well-known member
Absolutely valid point. My original owners manual calls for 90W in the winter and 140W in the summer, I guess I'll see if Tractor Supply has some straight 140W
GreenMonster48
Well-known member
I'm not sure...I'm just going by what was recommended for the 48 F-1 which used the gear box similar to the 39 toploader
CWPASADENA
Well-known member
There are lots of opinions about oil and what to use.
Here is mine.
What I have been doing for seven or eight years now is using modern Manual Transmission Oil in the Old Ford Transmiossions I have built for myself as well as other people. It is THIN and allows the brass blocker rings to work MUCH BETTER. With thinner oil, the blocker rings do not have to push a lot of thick oil out of the way to be able to grip the mating clutch surface on the gears. Also, it is not sensitive to temperature. The transmission will shift just as well cold as hot. Modern thin Manual Transmission Oils do an outstanding job of lubricating the Ford Transmission. They are used in applications where there are a lot heaver loads on the bearings and gears then encountered with the early Ford Transmissions.
The problem with thin oil is it will leak out easier then thick oil if you do not have the transmission sealed up well. With the old Ford Transmissions, I use SEALED front Main Drive gear and rear Main Shaft ball bearings. I remove the inner seal to allow lubrication of the bearings. I seal the Counter Shaft and the Reverse Idler Shaft and put a little sealer on the threads of the drain and fill plugs. I have used Red Line Manual transmission oil, Pennzoil Manual transmission oil and also GM Manual Transmission oil. I think the G.M. and Pennzoil is the same stuff.
Manual transmission oil is made specifically for Brass Blocker ring type transmissions, which is what the early Ford transmissions are.
Please note, almost all of the gear oils are also farmulated for clutch type Limited Slip Differentials and has a "Slip Agent" in it to keep the clutches from grabbing. If the container says "sutible for limited slip Differentials", it will have the "Slip Agent" in it.
SLIP AGENT is what you DO NOT WANT in a blocker ring transmission as it will cause the blocker rings to also want to slip during engagement and not grab the gear properly.
Please, before you say this will not work, try it, you may be supprised. Worst case, you will have to drain it out and put the old thick gear oil back in your Trans.
Again, this is my opinion based on my experience.
Chris
Here is mine.
What I have been doing for seven or eight years now is using modern Manual Transmission Oil in the Old Ford Transmiossions I have built for myself as well as other people. It is THIN and allows the brass blocker rings to work MUCH BETTER. With thinner oil, the blocker rings do not have to push a lot of thick oil out of the way to be able to grip the mating clutch surface on the gears. Also, it is not sensitive to temperature. The transmission will shift just as well cold as hot. Modern thin Manual Transmission Oils do an outstanding job of lubricating the Ford Transmission. They are used in applications where there are a lot heaver loads on the bearings and gears then encountered with the early Ford Transmissions.
The problem with thin oil is it will leak out easier then thick oil if you do not have the transmission sealed up well. With the old Ford Transmissions, I use SEALED front Main Drive gear and rear Main Shaft ball bearings. I remove the inner seal to allow lubrication of the bearings. I seal the Counter Shaft and the Reverse Idler Shaft and put a little sealer on the threads of the drain and fill plugs. I have used Red Line Manual transmission oil, Pennzoil Manual transmission oil and also GM Manual Transmission oil. I think the G.M. and Pennzoil is the same stuff.
Manual transmission oil is made specifically for Brass Blocker ring type transmissions, which is what the early Ford transmissions are.
Please note, almost all of the gear oils are also farmulated for clutch type Limited Slip Differentials and has a "Slip Agent" in it to keep the clutches from grabbing. If the container says "sutible for limited slip Differentials", it will have the "Slip Agent" in it.
SLIP AGENT is what you DO NOT WANT in a blocker ring transmission as it will cause the blocker rings to also want to slip during engagement and not grab the gear properly.
Please, before you say this will not work, try it, you may be supprised. Worst case, you will have to drain it out and put the old thick gear oil back in your Trans.
Again, this is my opinion based on my experience.
Chris
Last edited:
steve-cook
Member
1oldtimer
Well-known member
looks like the same stuff i bought from vintique.
it works good, but as stated above it's a little tough getting it into second until the fluid warms up, but leaks out slowly
. i was having a hard time finding regular (non gl5) around here and the local reto stop had that in stock.