Manual Transmission oil

24526 Views 34 Replies 12 Participants Last post by hitek14, Oct 28, 2015

jaylorenzo

Discussion Starter · Oct 27, 2015

Hi I have a 1965 mustang with an original Ford 4 speed. I want to change the transmission oil, but I don't know which oil I should use.
Also, I daily drive it pretty much every day, not really in the winters but I will need an oil that can operate at lower temperatures (Nothing crazy, like I use 10w-30 and it works fine. I live in SLC, UT if anyone is familiar) But I have noticed that when I change gears in the morning (fairly cold), it shifts hard. But then warms up and functions better. So i know that is normal, but i am debating about switching to a lower viscosity. Anyways, I would love to hear any input! THANKS!!

21 - 35 of 35 Posts

IndyFive-O

· #21 · Oct 28, 2015

Fastback97 said:
Go to your local Ford dealer parts counter and order 2 quarts of XT-4-QGL.

Motorcraft SAE 75W-90 API GL-4 Gear Oil.

I just picked up some of that last month and changed out mine, shifts great.

happystang

· #22 · Oct 28, 2015

Avoid GL5 gear oil. It eats up the synchros.

zray

· #23 · Oct 28, 2015 (Edited)

happystang said:
Avoid GL5 gear oil. It eats up the synchros.

I've herd that many times, but no one has ever proven that actually takes place. Funny how Mobil 1 75-90 which is GL5 rated hasn't degraded the synchros in any transmission I've used it in. You'd think that after 10-15 years there'd be some evidence that the synchros didn't get along with it. The fact is, all synthetic lube is not formulated the same. One brand might work, while others won't do so well. It's probably best to take each brand on its on merits.

Just use whatever is working for you seems to be the prevailing thought.

Z

Brian Conway

· #24 · Oct 28, 2015

QUOTE=IndyFive-O I just picked up some of that last month and changed out mine, shifts great.

Was there a noticeable change in your trans/shifter behavior ? The advertisement for the Motorcraft XT-4 QGL Transmission Gear Oil says it has friction modifier added. Anyone else tried this stuff ? Thanks, Brian

IndyFive-O

· #25 · Oct 28, 2015

Brian Conway said:
QUOTE=IndyFive-O I just picked up some of that last month and changed out mine, shifts great.

Was there a noticeable change in your trans/shifter behavior ? The advertisement for the Motorcraft XT-4 QGL Transmission Gear Oil says it has friction modifier added. Anyone else tried this stuff ? Thanks, Brian

Nope.
I am not sure what the PO had in there but there was no difference after I changed it. Which is fine because it shifted great before the change, I just did it so I know it's fresh.

Kid Mechanic

· #26 · Oct 28, 2015

After all this back & forth, I've heard that the original poster sold his car and now takes the local bus.

zray

· #27 · Oct 28, 2015

Kid Mechanic said:
After all this back & forth, I've heard that the original poster sold his car and now takes the local bus.

ahhh, the way of the world. A lot of hot air gets blown around, and at the end of the day it's unclear what the fuss was all about.

Z

Kid Mechanic

· #28 · Oct 28, 2015

zray said:
ahhh, the way of the world. A lot of hot air gets blown around, and at the end of the day it's unclear what the fuss was all about.

Z

I was hoping someone would find this funny and bring back a modicum levity.

Thanks for helping Z.

Fastback97

· #29 · Oct 28, 2015

Brian Conway said:
The advertisement for the Motorcraft XT-4 QGL Transmission Gear Oil says it has friction modifier added. Anyone else tried this stuff ? Thanks, Brian

My 4spd Toploader has 65k orig. miles and sat for a long time so a drain and fill of XT4QGL, about 500 miles, drain and refill of XT4QGL it now shifts like butter.

zray

· #30 · Oct 28, 2015

Brian Conway said:
QUOTE=IndyFive-O I just picked up some of that last month and changed out mine, shifts great.

Was there a noticeable change in your trans/shifter behavior ? The advertisement for the Motorcraft XT-4 QGL Transmission Gear Oil says it has friction modifier added. Anyone else tried this stuff ? Thanks, Brian

I've noticed that many of the well known brands in both the GL4 & GL5 do have a. Friction modifier added, Mobil 1 calls their lube 75w-90 LS and 75w-140 LS, with the LS meaning. Limited Slip. The budget brands make no mention of a friction modifier additive.

Z

supershifter2

· #31 · Oct 28, 2015

Kid Mechanic said:
After all this back & forth, I've heard that the original poster sold his car and now takes the local bus.

i think i saw him on the bus earlier. its was packed so it was hard to see all the people.:shocked::shocked::shocked::shocked:

jaylorenzo

Discussion Starter · #32 · Oct 28, 2015

Kid Mechanic said:
After all this back & forth, I've heard that the original poster sold his car and now takes the local bus.

Hahaha not yet! Ha I am just glad for all the input!

jaylorenzo

Discussion Starter · #33 · Oct 28, 2015

Not taking a bus… yet. Ha JK

Haha Thanks everyone for their input! It was kinda fun to read through all the replies and such! Luckily I have not had to take the bus yet! I think that I am going to end up going with conventional oil because thats what they had in the 60's, but thanks for all of your input!

Brian Conway

· #34 · Oct 28, 2015

For those with an interest; there is a difference between GL 4 and GL 5. The 5 is not the same or better than the 4. A little google search will reveal some little known info. Thanks for the replies on the MOTORCRAFT XT-4. Brian

hitek14

· #35 · Oct 28, 2015

I use Valvoline 85w-140. I hammer my car ever time I take it out so I like the extra cushing. I shift it at 7k with no issues.

21 - 35 of 35 Posts

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