Loud bang, dead rover - transmission?

[Apis Mellifera]

First, don't make it make those noises any more!

Second, remove the OD and I bet you'll find a stripped OD clutch sleeve.

http://www.faireyoverdrive.com/images/ClutchSleeve&BearingRTC7170&71.jpg

The reason you see movement when the OD is in N is because it is free wheeling and the TC, immediately downstream, is no longer providing resistance (trying to make the truck move) and so the clutch sleeve doesn't slip. When it goes into gear, the clutch sleeve isn't strong enough to make the truck move so it slips. The clutch sleeve is a square-cut gear/bearing thing (pictured) that bolts onto the output shaft of the gearbox. It goes into and drives the OD. Sadly, if the easily-replaceable clutch sleeve is toast, the not-so-easily-replaceable driven gear in the OD is toast too.

That's my (revised) theory, anyway.

[brucejohn]

Nick, I was just wondering how you were coming yesterday.

If my truck was showing these symptoms (no movement in gearbox or overdrive) I would be inclined to pull the transmission off. I will be interested to hear what the experienced rover mechanics suggest.

Edit [Oops, I missed that the gearbox is moving when the overdrive is in 'neutral'. Scratch pulling the transmission. (just paint a big "L" in my forehead)]

Sending good thoughts your way.

[NickDawson]

Nick, I was just wondering how you were coming yesterday.

Edit [Oops, I missed that the gearbox is moving when the overdrive is in 'neutral'. Scratch pulling the transmission. (just paint a big "L" in my forehead)]

Sending good thoughts your way.

Dont count yourself out yet - you may still be very right... the gearbox is not moving at all from what I can tell.

At least there is no movement from the gear I can see in the most forward of the access panels - is that the gear box?

[NickDawson]

First, don't make it make those noises any more!

Second, remove the OD and I bet you'll find a stripped OD clutch sleeve.



That's my (revised) theory, anyway.

Thanks Apis - I'll see if I can get it off and see what comes next.

[NickDawson]

OK! This is getting fun I love this board - post a video, get some input, go back out and start turning a wrench. Thanks guys for all the help and support.

Pulled the OD and found a nice shiny gear / shaft and guess what, it spins with the engine and no more ghastly sound!

http://www.youtube.com/watch?v=mSm2-riZrhc

So does that mean the OD is toast? I cannot see anything in the clutch shaft (is that even what this is?) that looks stripped. I also cannot see any way to get into the OD any further than I already am.

What are my next steps? Can I order a factor gear and back plate for the transmission and start motoring again? If I want to attempt to repair the OD how do I go about it?

Here's looking into the shaft of the OD. I bumped the contrast, at least as much as one can do with an iPhone photo. The teeth in there do not feel stripped.


Here's the gear/shaft from the transmission, it also looks and feels solid

[Apis Mellifera]

Post a closer/larger picture of the inside of the OD where the clutch sleeve mates.

The thing in the square (attached picture) is the clutch sleeve, which I linked above. The arrow points to the gear. If you're lucky, the input shaft of the OD (the female geared portion that mates with the arrowed gear) is not damaged. If that's the case, you could simply replace the clutch sleeve. If the OD is damaged, I'd recommend either having RDS rebuild it or possibly more economical, buy a replacement secondhand OD.

[rovers2a]

i believe you can rebuld the over drive. that exact same thing happened to our over drive. once on the dormi and once on the 109. both times stranded on the highway. FWIW forget about the over drive option they only last around 40-60 anyway. also when engaged they exert presure on the transmission bearings, ever noticed that the whinning is louder with over drive engaged. better off with high ration transfer box or high ratio diffs, if you got freewheel hubs dump those too. or next will be railko bushings. at least you got a quick easy fix, and not a new transmission. good luck

[NickDawson]

Good excuse to go play with a new lens
More on flickr
Im not entirely sure I understand this clutch sleeve thing - the part Alpis drew the arrow on spins now and I think is in normal shape. Although now that I look at the picture up close, maybe it is chewed up (though it does not feel like it is)... Im also thinking about that loud bang that is the title of this thread. How would a shredded female gear cause that bang?


heres a better shot of the inside of the OD's shaft - which also looks in good shape

[SafeAirOne]

I admittedly have a limited understanding of how the overdrive works, but presumably the input for the OD is in the center, driven by the gear that is under the spline nut on the transmisision output shaft. The OD output is through the gear around the outer circumference of the front of the OD, which engages the input gear of the transfer case.

Without the OD installed, the OD doesn't spin (duh!) AND the transfer case doesn't spin either, so your problem may be in either unit. The pitch of the nasty noise should change when you engage/disengage the OD in either case.

If it were me, I might try to eliminate the transfer case as a cause. I'd probably jack up one back wheel so it can spin freely, then put the transfer case in neutral and spin the handbrake drum and see how it feels. Then I'd probably put it in 2wd high and see how it feels and watch to see that the transfer case input gear (where the OD outer gear meshes) spins.

I might also drain the transfer case oil and see if there's anything in there that suggests damage.

I didn't bother to re-read this whole thread--I don't remember if you eliminated the transfer case shift system or not (the transfer case might not be fully shifting into gear. If it was only partially engaged and slipped out of engagement, it would do so with a loud pop or bang, such as you experienced originally.

It might be that you just cant fully engage the transfer case gears for some reason now and they may just be barely touching as they begin to meet, causing your horrible noise.

I've heard of people damaging those thin caps on the front of the transfer case that house the shifter rods, which caused their transfer case to not engage properly (see red arrow, below). Have you checked those for external damage/dents?

[Apis Mellifera]

I admittedly have a limited understanding of how the overdrive works, but presumably the input for the OD is in the center, driven by the gear that is under the spline nut on the transmisision output shaft. The OD output is through the gear around the outer circumference of the front of the OD, which engages the input gear of the transfer case.

Yes.

I don't know why the part is called a clutch sleeve. Basically you need at least a clutch sleeve and an input shaft for the OD. Both of them are seriously broken. What I've labeled the mainshaft is actually the gearbox output shaft. I'd guess the loud bang was the combination of the last bits of metal holding the clutch sleeve and OD input shaft in contact letting go and the resulting drive train shock when it did let go. The parts look greased so who knows why they wallowed themselves to death. Sometimes the nut on the gearbox output shaft is tightened with hammer and chisel. Usually it doesn't get tight enough that way. Your nut doesn't show evidence of this. If that nut is loose, it will let the clutch sleeve wobble. BTW, the bearing on the CS should spin, but the CS itself (geared area) should NOT rotate on the gearbox output shaft. It should be tight on the shaft.

[BackInA88]

The piece with the red arrow engages the spline teeth inside the overdrive and from the picture it looks to me that most of those teeth in the O/D are sheared.


Steve

[NickDawson]

The piece with the red arrow engages the spline teeth inside the overdrive and from the picture it looks to me that most of those teeth in the O/D are sheared.


Steve

I went out to feel around - they actually feel intact...then again, Im not sure what normal should feel like.
Im also going back to the loud bang- I can't imagine a gear sheering off be a bang so much as a grind.

[SafeAirOne]

AHH...I see what you mean. I couldn't tell with all that grease on there what the gear splines looked like, but upon close examination of the photos, it would appear that the gear on the inside of the OD is nackered. Can't tell about the drive gear on the transmssion shaft still. Either way, parts are available through RDS if I'm not mistaken.

...Just checked. I am not mistaken.

EDIT: Out of curiosity, is that the mainshaft that has the worn splines on the OD?

[NickDawson]

Yes.

I don't know why the part is called a clutch sleeve. Basically you need at least a clutch sleeve and an input shaft for the OD. Both of them are seriously broken. What I've labeled the mainshaft is actually the gearbox output shaft. I'd guess the loud bang was the combination of the last bits of metal holding the clutch sleeve and OD input shaft in contact letting go and the resulting drive train shock when it did let go.

Just saw your post Apis - I went out of order. Thanks for the markups on the pictures, helps a lot! If the teeth look trashed to you than thats good enough for me.

Am I still right to think that I can get the factory part, ditch the OD and be running again?

[NickDawson]

Either way, parts are available through RDS if I'm not mistaken.

...Just checked. I am not mistaken.

EDIT: Out of curiosity, is that the mainshaft that has the worn splines on the OD?

Thanks for the great input today SafeAirOne!

Do you think I should repair the OD or ditch it all together? I'd love to have it working again if that's a feasible possibility. Ill call RDS first thing on monday.