H151F manual gearbox rebuild

[frank rabbets]

I have not reread the thread. Are you sure the UJ's are greased properly? Grease needs to come out of all four legs of all four joints. Usually there is a lazy one on each UJ. Tranny noises are very difficult to track down unless there's an obvious cause or something fails. Also take the geae nipples off the sliding joints to relieve any pressure that may be in there.

I had a terrible noise on a car I rebuilt. Vibration and terrible noise throughout the tranny at anything over 40 mph. Everything had been stripped. Axle prop shaft gearbox etc etc. I swapped everything one at a time from a car a friend had in bits and nothing made any difference. I was lying under the car in a depressed daze for hours when I noticed the rear flange on the gearbox was pointing toward the ground, which it should do but the diff flange was pointing down also but should have been pointing up toward the gearbox. The 4 trailing arms had the same part numbers but when I got them off there were 2 short and 2 long. By some fluke I'd put the long ones on the top and the short ones on the bottom. Bingo and silence ! When I checked the release sheet from the factory there was a typed paragraph after test drive which said. "Manufacture and fit 4 trailing arms to rear suspension to correct alignment of rear axle ". Obviously that car had the axle points or chassis points welded in slightly the wrong place.

 

[Dave2000]

Just adding to Franks thoughts about the UJ's, if you take the car for a run before trying to grease them, then the old grease will be warm and it is more easier for the incoming grease to displace it. And of course watch for the regular vibe caused by over greasing the sliding joints.

regards

Dave

 

[Geoff Bart]

Hi all.

Drive train noise/vibration while driving at highway speeds is typical and not really concerning for a 20 year old vehicle with almost 350,000 km.

Truck had both D-shafts balanced and new UJs and yokes fitted around 12 months ago (6,000km) and have re-greased all but the very rear UJ (bothersome as you need to drop the rear shaft to get at the nipple) at least once since then in. Note to self: grease rear UJ.

Did notice the D-shafts held their grease very well after they were overhauled (pressurised the slack in the spline when grease pumped in but expected that the grease would work its way down the splines after a few tips. Certainly noticed where it had been "spun up" onto the body (at the spline joints/seals) while changing oils over the last week or two so its certainly made its way effectively along the drive splines and out the joint over time. Don't think there would be any remaining "pressure" but easy enough to spin out the grease nipples to check.

Back to my original post, the most worrying noise is coming from the gearbox/transfer while at idle (transfer in neutral) and 4th or 5th gears selected. As noted in the earlier posts, it is "rumble" like small stones being turned quickly over and over in a tin of oil. That's the best description I've got I'm afraid . Maybe like a big dry roller ball bearing.......but again, its only in 4th and 5th so I'm somewhat confident it rules out the main shaft/lay shaft bearings (as they're spinning in all gears). Total mystery at this point. Will just live with it I guess.....

 

[Dave2000]

Just putting the original post to one side for a moment. Unsure why you cannot grease the rearmost UJ? Never had a problem so unsure about that.

Pumping grease into the slider until it 'pressurised the slack' is IME wrong, the grease will not work it's way down and the pressure will be held for a considerable amount of time. Removing the grease nipples will not help, as you go over bumps the axle moves upwards, in effect shortening the distance between the transfer and axle, this increases the pressure. Removing the nipples and then driving over a bumpy road may help to expel excessive grease? The resulting pressure may have caused excessive wear on the differential pinion and the output bearings on the transfer case, or perhaps anther bearing in the TC, often causing a rumble.

Now returning to your original post, is it possible the over greasing has brought about the demise of a bearing in the transfer, or it was already worn and the prop shaft overhaul simply finished it off?

Regards

Dave

 

[Geoff Bart]

Hi Dave,

re the greasing of the rearmost UJ..........think it depends on the type/brand of uni-joint. I use Hardy Spicer units as over the years have found they seem to outlast most other brands. The grease nipple on these units in the rear tail shaft are located tightly in the inner cross and there is very little clearance. I could grease the rear-most uni-joint when I first purchased the vehicle (before shafts were balanced and uni-joints replaced) as while the nipple was in a similar position was just able to get the grease gun connection on it.

The new unit at the front of the rear drive shaft is the same but can get a connection on it (if its in just the right position). Rear is no chance due to the more acute angle between diff input flange and driveshaft yoke. Have heard a few other owners comment on the same issue. The fronts are not a problem with the Hardy Spicer units as the nipples are in one of the four caps on each uni-joint and hence are fully accessible.

Re the greasing of the driveshaft splines. Yes, thinking about it further if there was any pressure held for any extended period I guess it is conceivable that it may put some pressure/thrust on the transfer output and diff pinion bearings. However, fortunately I don't think that is the issue in this case though as the "rumble" I have concerns about is only evident when vehicle is stationary (transfer case in neutral) and idling in 4th or 5th.

There is no significant vibration/rumble whatsoever (apart from typically normal drive train noise for a 20 year old 4WD) when vehicle is in motion at pretty much any speed. Just a Very Very Very minor "zizzy" whine which can only be induced when "coasting" between power and engine braking if in either 4th or 5th gear. (It is barely noticeable and of a much lesser concern, at least at this point.......)

Thanks for the comments/thoughts.

 

[frank rabbets]

I was thinking of early stage pressure in the sliders where there is trapped air in there slightly compressing the tranny bearings even when not moving telescopically.

 

[buzz66]

I have a 76 Landcrusier 2013 model with the H150 box. Travelled only 110,00 KM's.
It has a high amount of overrun whine in 1st and second gear only. Seems to be dead quiet loaded or unloaded in 3rd 4th and 5th.
TQ input in 1st and second gear whine can also be heard but its bearly noticable. Gear changes in all gears is normal.
I'm about to drain the oil and take a look. since 40,000 kms it has Castrol Syntrans 75W85 and changed every 40,000.
Its due in another 10,000 but I will pull it now and change it with a cheaper gear oil if I find anything bad when I dump it.

My guess is the 1st gear thrust washer is broken or worn...ohh and the Engine produces close to 900 nm of TQ at the flywheel.

Oil turns out pretty black and I'm sure it has very fine metal....3rd and 5th gear with load and no load moves back and forth a significant amount.
very litle or no movement in 1st 2nd or 4th. I thinking it has more than 1 issue now

 

[Cortooncowboy]

Hi guys , I’m just in the middle of a predicament, my gearbox was not working right, took it out and split it and long story short I think I have found my problem, I just wondering would any of ye chance putting back in with this damage, 3 teeth broken off 3rd gear, not off the gear but of the synchro part, I will attach pictures. My problem is I’m getting married in 3 weeks and would love my wedding to be my debut with my 80 series on the road!

 

[Iwan]

You will have to separate the mainshaft and evaluate the components that need renewing.

Only one thing to do is to follow the FSM.. and replace the problem parts.

You can do it because you've got this far into the job!

"Can't give advice in marriage guidance because it may take time to get the replacement pieces!"

 

[Cortooncowboy]

ah the marriage guidance will come in an apparition I reckon!
Thanks for reply, I decided earlier to clean the parts and assemble the box again thinking I had it sorted once I found the wee bits but it turned a few times and then I heard a slight click and the shaft locked again, messed around a bit changing gear and got mad with it and cursed a bit and then it freed itself out again, and it hasn’t locked up again, would it be dodgy to chance it. I really want to have it for the wedding, I will take out box and rebuild it again if I got 1 day out of it! It’s like another gear is selecting itself and then frees out, but I can’t see anything else wrong in the box itself?

 

[Cortooncowboy]

I’m thinking 3rd gear since it’s the damaged one!

 

[frank rabbets]

I've seen several boxes with your problem, only one tooth off though. the missing teeth do not affect the correct working of the box so long as the ring itself is sound and not broken. They do not show symptoms so I guess you may be barking up the wrong tree in the first place,
What problem do you have? If it's stiff gear change that is not a problem but normal.

 

[Cortooncowboy]

Hi frank, no it changes up through the gears perfect, even reverse, my problem is the box some times feels like it’s would up and tight like the centre diff is locked, when driving and push the clutch the whole jeep shudders like the pressure is let off,I have gearbox out on bench and when I turn input shaft output shaft is locked when in neutral, then it’s like something clicks and it all comes back to normal, that’s when I split the box and found the 2 teeth but 3 are broken, I can’t see anything else wrong or broken but I didn’t split the shafts, I put it all back together lastnite and tried it and it “locked” once more and then after messing a bit it came free and hasn’t done it again, would it be wishful thinking that it was just everything getting back settled and it might be ok? Sorry I might be bad at explaining by text.

 

[Dave2000]

Not doubting your mechanical skills and cannot remember if you have the transfer case off? But at this stage in the game without going any further I would take the gearbox to a gearbox specialist and ask them to look at it, I really do offer sympathies in this case, my BMW started leaking from the fuel tank a week before my marriage, so my best man was doing the runaround with bridesmaids on the day in his car a beautiful Granada when and his auto transmission packed up! The wedding went well and to go on our honeymoon my parents lent us their Hillman Hunter, proper car that, it had recently been resprayed after an accident so it did look pretty good, driving to our honeymoon at night in the rain I found it odd that the rain was Maroon! It turns out the 'Good luck' and 'Just Married' and other messages sprayed on the car with shaving cream had dissolved the paint! The following morning the messages were still there......... in gray primer!

Was someone trying to tell me something? YOUR DAMN RIGHT THEY WERE!

Regards

Dave

 

[Cortooncowboy]

Jez that was a hard one to explain with the shaving foam!! And I taught I was having problems! You had a lot of auto carnage to repair after your wedding!!
Ya I’m a plant mechanic so not a stranger to skinning the odd knuckle! I have the transfer box off and in bits beside it on the bench cause originally I taught (hoped) the problem was in there and it just wasn’t disengaging the centre diff!
That is another problem and why I went at it myself , i have rang a few gearbox repair centres here in my part of Ireland and some won’t touch it because of age of the jeep and in case they won’t get parts and then others are giving me the runaround not answering and supposed to ring back but don’t. So I said to hell with ye all I will sunder it myself!

 

[Dave2000]

Go for it, even if you get married without the 80, you can always use it the second time around! Dave runs for cover.

Regards

Dave

 

[Cortooncowboy]

thanks for your sage words of wisdom and marital advise!

 

[frank rabbets]

It could be that your problem is with the lower "layshaft" seizing up as the input shaft is geared to that all the time. Unheard of really though.

Try and see if you can get it to lock up with it all assembled and held in vice via centre plate. Sorry not very helpful.

 

[Cortooncowboy]

No thanks a million , every bit is a bit of help.

 

[frank rabbets]

I would make absolutely sure the problem is in the main box and not the transfer. The main boxes generally don't give trouble but the transfer boxes have been known to give your symptoms. Dave2000 had a similar run around I think.