H55F oil: Red Line MT-90 versus Mobil Delvac 50 versus Lucas (1 Viewer)

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Spook50

Spook50

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Going to open up a can of worms here (intentionally), but I'd like to know what those of you who've tried both oils in your H55F prefer, and what climate you're in. Where I am goes from 100+ in the summer and can get down to sub zero temps in the winter. I currently run the Red Line and until my synchros started showing wear, it's worked very well in summer and winter conditions with minimal noise and smooth shifts. Before that I ran a Lucas GL4/GL5 gear oil that was okay, but the Red Line was a noticeable improvement. Primarily in noise. Shifting felt just fine though.

I haven't tried the Mobil yet but I hear good things about it, so I'm tempted to try it when I change my oil before winter really kicks in.

Curious to hear others' opinions.
 
I used normal gl5 for 1000 miles and then Mobil 50 for 35,000 miles.

The h55f and new georg built t case are loving it. I really didn’t even need to change the fluid yet, but I was bored. I’m going to try and run this current fluid for another 60,000 all the way to 400k.

Trans on top with more deposits (brand new) and a rebuilt split case plug on the bottom.

The fluid is a little thick for the first 10 mins and slow to shift, but works great the rest of the day when it’s below freezing.

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I used the Mobil Delvac 50 in my cruiser.
As Mobil stated, “it’s a 90 wt synthetic gear oil on the high end of the 90 wt scale.”
Yes it’s still technically 90 wt but it’s thicker than any 80w-90 gear oil. Definitely not as viscous as a 140 wt gear oil
You’ll feel the difference immediately when shifting and you’ll hear it too. Transmission runs quieter because the oil film is thicker.
When it warms up, shifts are smooth (except for the 2nd gear downshift on the H55F which always was tricky on my H55).
I really liked it but I could definitely feel it’s thicker viscosity-on a cool morning. When it warms up it’s superb.

If I lived/drove in a place that froze in the winter, I’d probably use a 75w-90 wt oil instead - like that redline stuff.

It’s kinda expensive (I got mine a ZORO) but I think it would be worth it to at least try it. It is an excellent warm weather gear lube.
If I lived at a ski resort, I probably wouldn’t use it. But any other place that’s not covered in ice - it’s great.
 
OSS said:
I used the Mobil Delvac 50 in my cruiser.
As Mobil stated, “it’s a 90 wt synthetic gear oil on the high end of the 90 wt scale.”
Yes it’s still technically 90 wt but it’s thicker than any 80w-90 gear oil. Definitely not as viscous as a 140 wt gear oil
You’ll feel the difference immediately when shifting and you’ll hear it too. Transmission runs quieter because the oil film is thicker.
When it warms up, shifts are smooth (except for the 2nd gear downshift on the H55F which always was tricky on my H55).
I really liked it but I could definitely feel it’s thicker viscosity-on a cool morning. When it warms up it’s superb.

If I lived/drove in a place that froze in the winter, I’d probably use a 75w-90 wt oil instead - like that redline stuff.

It’s kinda expensive (I got mine a ZORO) but I think it would be worth it to at least try it. It is an excellent warm weather gear lube.
Click to expand...

I bought it on the suggestion of your alter ego. No regrets.
 
OSS said:
I used the Mobil Delvac 50 in my cruiser.
As Mobil stated, “it’s a 90 wt synthetic gear oil on the high end of the 90 wt scale.”
Yes it’s still technically 90 wt but it’s thicker than any 80w-90 gear oil. Definitely not as viscous as a 140 wt gear oil
You’ll feel the difference immediately when shifting and you’ll hear it too. Transmission runs quieter because the oil film is thicker.
When it warms up, shifts are smooth (except for the 2nd gear downshift on the H55F which always was tricky on my H55).
I really liked it but I could definitely feel it’s thicker viscosity-on a cool morning. When it warms up it’s superb.

If I lived/drove in a place that froze in the winter, I’d probably use a 75w-90 wt oil instead - like that redline stuff.

It’s kinda expensive (I got mine a ZORO) but I think it would be worth it to at least try it. It is an excellent warm weather gear lube.
If I lived at a ski resort, I probably wouldn’t use it. But any other place that’s not covered in ice - it’s great.
Click to expand...
Sounds like it's definitely worth the try. I'm very curious to see if there's any difference good or bad in shifting overall versus the Red Line before I tackle a rebuild. Another thing prompting me to rebuild is I now have oil migrating into my transmission, though very slowly. It took a year for about half a quart or so to move over, so I won't bother with the tube fix but will be more diligent about checking levels regularly until I pull it apart.

Funny too that you mention the 2nd gear downshift issue, same that I now have. But now that I know it's not a rare issue though one that mine hadn't had before, I'm encouraged to go ahead with the rebuild also for the sake of new synchro assemblies.

@HemiAlex what had you running the GL5 initially on your rebuild? Is that just what it had been filled with, or were you advised to?
 
Just cheap stuff that I knew I'd change quickly after a little break in. I didn't want to overthink it, which I normally do.

I think that my h55f shifts amazingly. I'm not nice to it at all, and I definetly don't drive my truck like a truck...It is full race tractor for me. I've almost hit 40,000 miles since install and dare I say, it shifts just like my 300,000 mile h42f.

It never is notchy, and doesn't lock me out of shifts if I'm a little fast letting off the clutch.
 
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I only use MT90 in toyota manuals. On my old firstgen 4runner my w56 5speed that i swapped in was old and beat. Put the MT90 in and it smoothened it out quite a bit. On the flip side i bought a brand new marlin HD w56 and ran redline from day 1 and that thing shifted like a car transmission. I ran MT90 in my H55f as well. Now that im running an auto im using Redline ATF.

I think what you got in there is one of the best you can get!

The only other oil i wanted to try out was MOTUL Gear 300 75/90. It says its a GL4/5 but safe for brass syncros. Redline and Motul are pretty much the best of the best id think
 
HemiAlex said:
Just cheap stuff that I knew I'd change quickly after a little break in. I didn't want to overthink it, which I normally do.

I think that my h55f shifts amazingly. I'm not nice to it at all, and I definetly don't drive my truck like a truck...It is full race tractor for me. I've almost hit 40,000 miles since install and dare I say, it shifts just like my 300,000 mile h42f.

It never is notchy, and doesn't lock me out of shifts if I'm a little fast letting off the clutch.
Click to expand...


Spook50 said:
Sounds like it's definitely worth the try. I'm very curious to see if there's any difference good or bad in shifting overall versus the Red Line before I tackle a rebuild. Another thing prompting me to rebuild is I now have oil migrating into my transmission, though very slowly. It took a year for about half a quart or so to move over, so I won't bother with the tube fix but will be more diligent about checking levels regularly until I pull it apart.

Funny too that you mention the 2nd gear downshift issue, same that I now have. But now that I know it's not a rare issue though one that mine hadn't had before, I'm encouraged to go ahead with the rebuild also for the sake of new synchro assemblies.

@HemiAlex what had you running the GL5 initially on your rebuild? Is that just what it had been filled with, or were you advised to?
Click to expand...






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I've used all the above plus Sta-Lube, Mobil1, Castrol, Amsoil, Shell Spirax ...

MT90 seems to shift the best for shifting smoothness

Mobil 50 is good, too, but I'm not in a cold area.

Can't comment on wear since I've never had the H55's apart

Honestly, anything you use of the proper rating is fine, and it's more important to do frequent oil changes (15/20K of 'severe' use, which means normal driving, to me), than the brand. Even the Sta-Lube is Mil Spec.

Sta-lube is all one of the long-time Cruiser shops around here uses, and they've been at it 30+ years.
 
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All I've used is GL4 Sta-Lube. I have somewhere well over 100k on the H55F that I purchased new and with the $$ of the transmission I've only used GL4. I have no issues with up or down shifting, sometimes a little notchy but it's always been that way. When cold shifting is not smooth in 1st or 2nd so I go easy with it, maybe double clutch, but once warmed up no issues.
 
Godwin said:
All I've used is GL4 Sta-Lube. I have somewhere well over 100k on the H55F that I purchased new and with the $$ of the transmission I've only used GL4. I have no issues with up or down shifting, sometimes a little notchy but it's always been that way. When cold shifting is not smooth in 1st or 2nd so I go easy with it, maybe double clutch, but once warmed up no issues.
Click to expand...
It definitely seems the most critical factor in whatever fluid is chosen is that it be a GL4, so that's what I've insisted on using myself as well, especially since it seems safe for the transfer case as well, so makes it easy to keep the same oil for both tranny and transfer.
 
I run Redline synthetic MT90 in all my Toyota manuals. I’m sure lots of other brands are just as good but I was impressed in the difference it made in my 85 4Runner many years ago and have had no reason to switch to something else.
 
Going from regular 80/90 dino oil to Redline made it seem like I'd installed a new transmission. I did it specifically 'cause I'm in moderately cool weather and the transmission was very stiff until it got warmed up. There is no morning warm up time necessary with Redline. None.
 
I'm running Redline in Transfer and transmission only. I've got an Aussie locker and I'm not sure how it would like the synthetic oil. Maybe thats my next internet info search...

I'm also running Redline ATF in the steering box, and it also seems pretty happy.
 
I used this stuff (as it was like $85 when i bought it) Only using it till 1st flush after new H55 and Tcase but i think it shifted ok.... @mattressking would know better than me lolol.


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