H55 Fifth gear troubles

[WrenchMonkey]

just put a used H55 in my truck tranny runs smooth 1st thru 4th and reverse but doesnt want to get into fifth kinda feels like it goes in but then its just half way when I let out the clutch and it grinds will go in fine at low speed just not when i need it like highway driving could this be because of the fluid I'm running. or does some of that 5th gear linkage need adjusting any suggestions id love to hear them. replace bushings and ball in shift tower already.

 

[crushers]

sounds like time to replace the hub assembly.
should be able to get these from Radd Cruisers on the island or Extreme bends in Vancouver.

 

[blis]

you could always try different oil in gearbox but if it doesnt fix it then you will most likely have to pop open the tranny and see for yourself...

 

[Michael Hanson]

The fifth gear seems to be the one on used trans. thats always out . Probably need to figure its out when buying these. Mike

 

[keving]

Does 5th gear sit high in the trans? Do they have a tendency to run dry if the trans oil isn't topped right up.


I recall having a trans with this issue once, can't remember what it was; but I was advised to tilt it a bit when adding fluid so I could add slightly more oil to the trans...then fifth would not run dry.

 

[Kynot62]

5th gear does sit high but the gear on the countershaft that actually drives 5th is almost submerged in oil so going dry is not realistic. Realistically the counter shaft is submerged in gear oil throwing oil all around the inside of the case including 5th. And this oil slinging around is what runs down the front of the tcase and is directed into that plastic oiler that feeds oil to the hub assembly that contains the synchro.

Is there a difference shifting between hot and cold gear oil?

Baring any other damage or wear of the gears themselves, if it won't easily go into gear, ie just grinds when trying to shift, you might try just changing the synchro ring not a difficult fix and doesn't require a total tear down of the tranny, even if you do have to pull the tcase to access everything. Toyota was nice enough to put all of the fifth gear parts outside of the main case. Nor do you need to replace the entire hub assembly as most of the wear tends to be on the brass synchro ring.

If it is the synchro ring, changing oil is not likely to fix the problem. My 3rd gear synchro went and changing to synthetic oil made all the other gears smoother but made 3rd not work at all. Going to a heavier wt oil made 3rd gear work but made the other gears horrible when cold and still didn't fix 3rd when hot. A new synchro ring solved the problem.

It is possible that the slot in the shift linkage (in the top cover) that puts it into 5th is excessively worn but I don't remember any specs given for it so it may require replacement of that rod in the top cover, not really a simple way to adjust this if it is out of whack, the FSM just shows how to put it back together and no mention is made of adjustments when doing so

Call Steve at EBI for his opinion, he has had a ton of these apart.

Tony

 

[blis]

Does 5th gear sit high in the trans? Do they have a tendency to run dry if the trans oil isn't topped right up.


I recall having a trans with this issue once, can't remember what it was; but I was advised to tilt it a bit when adding fluid so I could add slightly more oil to the trans...then fifth would not run dry.

On H55F fifth gear will have issues if it has been used as trailer hauler. I'm quite sure even the owners manual states that when pulling a trailer fourth gear is the biggest one should use...

 

[bigbrowndog]

On H55F fifth gear will have issues if it has been used as trailer hauler. I'm quite sure even the owners manual states that when pulling a trailer fourth gear is the biggest one should use...

As quoted above driving under 70Ks or towing in 5th gear forces the two gears apart
[friction forces from the cut of the gear teeth]. Because the gears are stuck on the outside of the bearing locations this causes the shaft to want to oscillate
and wear the bearing between the two main drive shafts which loads the front, center and back bearings. General wear lets the shafts move more causing further strain on the bearings. Most 5 speeds are built this way so it is no big issue. Later model single main shaft gearboxes still have problems also. H55F still a tough gearbox.

 

[cruizerbuddy]

I bought a used 5 spd recently and it wont move into 5th gear.
Took the tcase off and everything looks good.
Its almost like there needs to be a spacer in between the main trannu box and the 5th gear box?
Nothing looks overly worn amd yeah the rest of the tranny and tcase work fine.

Swapped it out yesterday with a known good and its working good but ill need this back for another 60..

 

[Jentuh]

As quoted above driving under 70Ks or towing in 5th gear forces the two gears apart
[friction forces from the cut of the gear teeth]. Because the gears are stuck on the outside of the bearing locations this causes the shaft to want to oscillate...

I can imagine that towing in fifth will give a continues high torque on the gears, forcing them apart, but when driving under 70Ks torque is relatively low on that motor RPM, and thus the forces pushing the gears apart is low.

Or do you suggest that's it's just the low RPM causing the oscillation, causing the damage?

 

[cruizerbuddy]

So it appears as though my 5th gear sgifting problem may be nothing more than a missing o ring thingy mcbob in the shifter housing area. Go figure....

 

[arnott1t]

ya sounds more like linkage or something than anything else to me. I'd look there

 

[Josh Melber]

I have the 5th gear issue on my h55f as well, already checked the shifter housing and I do have the shifter seat in and in good shape. I put a new shifter nylon cup on while I was in there but still having issues in 5th. I noticed if I shift into 5th, hold shifter in place and then give her some extra gas she will go in grind free but as soon as you let off the throttle it will pop out of gear. Been like this for a long time. 5th gear hub gear? Would this be attemptable with taking t-case down and leaving tranny in truck?

 

[cruizerbuddy]

just put a used H55 in my truck tranny runs smooth 1st thru 4th and reverse but doesnt want to get into fifth kinda feels like it goes in but then its just half way when I let out the clutch and it grinds will go in fine at low speed just not when i need it like highway driving could this be because of the fluid I'm running. or does some of that 5th gear linkage need adjusting any suggestions id love to hear them. replace bushings and ball in shift tower already.

so i had this happen and all it was was one of the spacers that resides under the shifter was missing. a local mechanic made the discovery after i had taken the unit to him with the same symptoms. i had a 4 speed lying around and he asked if i could produce one of these thick washers. i brought it back to him, we installed it and it shifted right into 5th gear with no issue. ensure you are not missing any of the parts that go within the shifter housing. it worked in my case. Mark

 

[Josh Melber]

Yeah I heard of that issue as well and on the bottom there was a rubber "seat" that was 2 part, one was black and the other part was blue. I think this is what you were missing...but let me know, I did have that in there and it looked to be in good condition. Then of course the little plastic cup which I got new from marlin crawler i replaced.

 

[WrenchMonkey]

Since this has been brought back from the dead, originally all my 5th gear components are were new, tranny was rebuilt by a trusted shop. Still popped out till the day I took it off the road, the whole truck is getting rebuilt as we speak