G52 Transmission Questions (1 Viewer)

[GreenPump]

My LN106 Hilux runs a G52 transmission identical to many domestic yotas. Those familiar with G52 tranny I need your input.

Lately I've experienced the following minor issues;

Hard upshift into 2nd occasionally

Slight grind/clicking when downshifting from 3rd to 2nd, or 4th to 3rd

If I shift more "carefully", slower speed, slower shift, I can get it to drop in nicely.
Is this typical of a G52? Or do I have worn syncros. I've tried some different oils, amsoil GL5 75w90 and Redline GL-4 oil. Of the two it seemed to like the Redline better. Transmission shop recommended giving Schaeffer's 50 weight a try.

Only 70k miles on this truck so I have a hard time believing the trans is beat up.

Could the shifter seat cause these type of issues? Easy enough to replace.

 

[GreenPump]

Here are the recommendations from both Gregory's and the FSM. Not looking promising.

Gregory's lists worn seats as a possibility for upshifting but not on the downshift.

 

[GreenPump]

Shifter seat looks fine. In fact, it looks like a Marlin Crawler seal and socket have been put in. Although I don't know how that is possible unless the importer did it in 2021.

I guess this means my G52 is on its way out??

 

[aztoyman]

I never had or worked on that model trans. I have had W56, R150 F and R151F. I have had the bad OEM shifter bushings crumble apart and cause problems. I have had them apart and rebuilt them. I was going to recommend the Marlin parts and looks like you already have them.

Mine did not shift smoothly with GL-5 oil. Kind of "notchy" feeling. Like the speed didn't match for the shift. Shifts MUCH better with GL-4 like Sta-Lube and Redline MT90.

Your trans is low miles and I wouldn't think it needed a rebuild already but you never know. Any metal in the oil or on the drain plug? Is the clutch in good working order?

I'd run the GL-4 myself and give it a while if you've had GL-5 in it. Some people call bull $hit on the GL-5 being a problem. This is MY personal experience and opinion. ALL mine have shifted noticeably better with GL-4.

 

[GreenPump]

Good to know. Redline MT-90 is what is currently in there.

As far as metal in the pan, the initial change there was a bit of very fine metal on the drain plug magnet. Equivalent to the size of a blueberry. The syncros are brass, so I'd have to strain the old oil and look for brass. But I didn't see anything visible to the eye. No chunks or flakes

 

[thetoyotaman]

I would recommend trying 80W-90 GL4 like Joe Gibbs with 50% Lucas Oil Stabilizer and see if this clears it up. Give it 1000 miles or so. Otherwise, synchros could be shot if wrong oil was introduced in the past.

 

[GreenPump]

I would recommend trying 80W-90 GL4 like Joe Gibbs with 50% Lucas Oil Stabilizer and see if this clears it up. Give it 1000 miles or so. Otherwise, synchros could be shot if wrong oil was introduced in the past.

After switching back to the GL4 redline, and driving for a week, all the gear clash on downshift is gone.

I guess it really didn't like that amsoil severe gear! My diffs and transfer case do though.

 

[thetoyotaman]

Sometimes they can be picky on the oil they like.

 

[mudandrock]

Did you try adjusting the length of the push rod on your clutch master cylinder? I’ve fixed a lot of “bad” transmissions that way… worst case scenario I know for a fact that the W56 will work as a replacement, just swap the bell housing.

 

[ntsqd]

I only ever ran Torco synthetic and Redline in my G trans. The singlular only time that I had trouble with shifting in ~120k miles was due to the T/O bearing fork. It had cracked and split over the top of the pivot ball socket and I wasn't getting full clutch release.