GL-4 vs. GL-5 gear oil for a Toploader.

[65ShelbyClone]

I have concluded that the search function on this site sucks half the time. I spent the last hour looking through old threads for an answer on this because I know it's been covered before, but kept getting hundreds of unrelated hits. It seriously needs the use of boolean operators and quotation marks for exact matches.

Aside from that, I need to change the oil in my Toploader to flush out the last bit of metal junk that came from my earlier findings documented here. I recall hearing people say that GL-4 was the only stuff to use because of something bad that GL-5 does to brass blocker rings or something.

Is this true at all? Does it even really matter in the end? I have enough 85w-90 GL-4 and 85w-140 GL-5 to use either type. Which one will be better?

 

[D.Hearne]

There's nothing high tech about a Toploader, use whatever you've got. Heavier the better for street use, if you're drag racing only, you could get by with something thinner possibly to reduce the drag. If you want an expert opinion, go to http://www.4speedtoploaders.com and see what David Kee recommends. I don't recall what I have in mine, but it was the first thing I grabbed off the shelf at the parts house and it's been in there for about 5 years now (and is daily driven)

 

[65ShelbyClone]

Thanks, I was hoping you would reply.

I'm kind of embarrassed that I forgot about Kee's site. According to him, "any grade of 75W-90" will work for a street-driven transmission while 80W-140 is fine for heavy duty and hot weather applications. I guess 85W-140 GL-5 is going in this time.

I can't help but wonder what all the commotion is about regarding GL-5 gear oil...

 

[D.Hearne]

I don't know, I don't pay any attention to the various spec ratings. I just stick to what works. I bought one Toploader that had sat for years outside under a tree with no top cover, dumped the dirt and leaves out, poured in used oil and diesel fuel and repeatedly drained and worked it till it was turning good as new. Later I bought a rebuild kit for it and when I pulled it apart , the needle bearings in the cluster gear looked like new. The dirt and moisture never got to em. I sold that one and another to David Kee. That's one dedicated man. He drove 450 miles to pick em both up the next day.

 

[65ShelbyClone]

Dedication indeed! I should have my old man offer his two Toploaders to Kee. One is a narrow pattern close ratio BB trans and the other is a wide pattern/wide ratio smallblock.

 

[D.Hearne]

Well you'll probably get more for em selling them outright (usually) But you could check with him and see what he's giving for cores now. When I sold those two, I had just been fired from a job and really needed the quick cash and what he offered for both was more than I had in them. He builds completely new units and goes thru the used ones to where they're damn near new, I think the only parts he reuses are the case, tailshaft hosuing & main shaft. BB units fetch premium prices on ebay.

 

[66HertzClone]

Be careful using a GL5 in the trans. The EP additive in the GL5 oil is corrosive to yellow metals, brass synchronizers. If GL4 is the preferred lube, you are better off using it to keep things working properly.

 

[mikethebike]

Mobil-1 synthetic gear oil. Use whatever viscosity you like, you cannot go wrong.

 

[65ShelbyClone]

What about Redline MT-90?