New Drivetrain into '78 BJ40

[seatosummit]

Thanks for the clarification, Tom.

Can you clarify what you mean by "muck around with the shim thickness"? Is it not as simple as swapping in a new seal? Also, with respect to temporary bandages on my bullet wound, will a different gear oil viscosity sooth some of the whine?

Noted on the importance of getting it handled. I suppose I can read more in to later but in short, how difficult is rebuilding a transmission? I know I can source a rebuild kit for about $500, but I am concerned about the required tools, expertise. etc.

 

[lostmarbles]

Thanks for the clarification, Tom.

Can you clarify what you mean by "muck around with the shim thickness"? Is it not as simple as swapping in a new seal? Also, with respect to temporary bandages on my bullet wound, will a different gear oil viscosity sooth some of the whine?

Noted on the importance of getting it handled. I suppose I can read more in to later but in short, how difficult is rebuilding a transmission? I know I can source a rebuild kit for about $500, but I am concerned about the required tools, expertise. etc.

When replacing a seal you have to check for abnormal play in the associated bearings. So, in the case of your transfer rear output seal, once you have the rear driveshaft disconnected (and the handbrake disengaged!) you need to see if there is any visible up/down or left/right movement in the brake drum relative to the backing plate. In other words - Is it able to "wobble" at all as it spins when you're driving down the road?

If there's wobble there, it is no good just replacing the seal because the new one will rapidly develop a leak too.

So then you'd need to remove the speedo housing and increase the shim thickness (if I recall correctly).

These rings in the first photo are the shims:

And here's a photo showing that rear output transfer seal still in the speedo housing (that sits inside/behind your handbrake drum)

Yes. Heavier oil will slow leaks and quieten noise but the FSM specifies a certain viscosity because that's what lubricates their transmission the best...

As for how difficult to overhaul, I haven't done one myself but there are a number of good threads on here from people who have. I don't think it's a job for the faint-hearted. (You have to enjoy a challenge and have mechanical expertise I'd say.)

 

[seatosummit]

When replacing a seal you have to check for abnormal play in the associated bearings. So, in the case of your transfer rear output seal, once you have the rear driveshaft disconnected (and the handbrake disengaged!) you need to see if there is any visible up/down or left/right movement in the brake drum relative to the backing plate. In other words - Is it able to "wobble" at all as it spins when you're driving down the road?

If there's wobble there, it is no good just replacing the seal because the new one will rapidly develop a leak too.

So then you'd need to remove the speedo housing and increase the shim thickness (if I recall correctly).

OK, very good. I will go through the process of determining wobble and report back. I just ordered new seals and will see about getting some shims, also.

Yes. Heavier oil will slow leaks and quieten noise but the FSM specifies a certain viscosity because that's what lubricates their transmission the best...

As for how difficult to overhaul, I haven't done one myself but there are a number of good threads on here from people who have. I don't think it's a job for the faint-hearted. (You have to enjoy a challenge and have mechanical expertise I'd say.)

Right, I realize it won't be an ideal configuration for the long term with an alternate viscosity, merely a means to limp along for a while.

As for the rebuild, I am considering doing it myself; though I admittedly lack mechanical expertise, I think I make up for it in eagerness to learn, and motivation to get my truck functioning properly. The abundance of resources around MUD certainly helps, too.

 

[seatosummit]

Progress has been made, Gents.

I backed off the max fuel setting by about 2 full turns, which made for an immediate reduction in black smoke from the tail pipe. Running about a gallon worth of B100, followed by a filter full of SeaFoam, and new filters all around seems to have all but eliminated any smoke issues. Looking at my original 3B, it seems the max-fuel setting was much further out (more fuel) than the setting on my current one. That being said, I didn't have any issues with smoke (at least after it was warmed up) on that truck. I would like to further investigate the best spot for that screw, but will hold off on that until I have a pyro/EGT meter.

Cut some ugly holes in the transmission tunnel to accommodate the new shifter locations. Still need to weld in some sheet metal to fill the old holes, and paint. I will post some photos when I get around to it. I am going to need to reshape the cane shifter also to ensure it doesn't hit my Tuffy box
.

I found some small rust spots on the floor pan on the driver's side. Cleaned, sanded, metal prepped and POR15'd. Then did a general POR15 once over.

Pulled the transmission and Transfer case fluids. Not surprisingly, the contents were pretty foul.

A few small aluminium shavings on the trans plug, but mostly just general gunk on the transfer.

I just got some Lucas Oil heavier weight Lucas gear oil in the mail to swap in after I do the shims and seals. Hopefully it will cut down on the bearing whine until I can rebuild the trans/transfer later this summer. Here is a video to give you guys a baseline of what the combo sounds like before I pulled fluids.



Also, I found the "literal needle in the hay stack"... my missing slave cylinder pushrod. Guess I can pull out the bolt that is in there now.

 

[lostmarbles]

Excellent that you found that missing slave pushrod - particularly since it is in such great condition (with most of the original plating intact)!

BTW - Those metal shavings must be steel (rather than aluminium) to have been attracted to your drain-plug magnet.

And that whine probably equates to gear-teeth wear (loss of hardening) ...and probably from the transfer gears if your transfer case has been losing oil to your gearbox over more than a short period of time..


Edit later... But our transmissions are noisy and I'm sure the noise from mine would be unbearable if I was running without a floor or floor mat.. so maybe it's not too bad?

 

[Brewsterfire]

Good work, moving along nicely.

Cheers

 

[seatosummit]

Excellent that you found that missing slave pushrod - particularly since it is in such great condition (with most of the original plating intact)!

Yep! Eventually found the second one that had fallen off of the old clutch setup also. Funny how you can spend hours looking for something, only to move on and find not just the one I knew I had, but an identical bonus part, within a day! Oh well.

BTW - Those metal shavings must be steel (rather than aluminium) to have been attracted to your drain-plug magnet.

Indeed.

And that whine probably equates to gear-teeth wear (loss of hardening) ...and probably from the transfer gears if your transfer case has been losing oil to your gearbox over more than a short period of time..



Edit later... But our transmissions are noisy and I'm sure the noise from mine would be unbearable if I was running without a floor or floor mat.. so maybe it's not too bad?

From what I can tell, the oil imbalance is not a new issue, by any means. After replacing all of the seals (shims were not needed, as there was negligible play in the output shaft/companion flange) I installed an external fluid balancer between the t case and gear box, http://www.man-a-fre.com/parts_accessories/oilreturnkittransmissiontransfercase.htm and filled with 80-140 Lucas gear oil. My hope being the balancer will help equilibrate things for a couple months while I prepare to rebuild.

I took it for a 20 or so mile test drive and found the noise from the drivetrain quite a bit more reasonable, hardly felt like my ears were apt to bleed, even at highway speed! As you mention, I think it will be a lot more reasonable with trans tunnel and carpet kit reinstalled. Also considering adding a noise deadening material on the underside of the tunnel.

Good work, moving along nicely.

Cheers

Thanks, Brewsterfire. Been enjoying watching your project come to life also.

 

[seatosummit]

I also ran a can of Liqui Moly through the 3B. Didn't do much, as I think the Seafoam and B100 did a pretty thorough job of cleaning my fuel system. But the smoke issue is taken care of.

Swapped in the proper 24V (20.5V actually) glow plugs. Starts immediately without hesitation now.

Working on welding up the new trans tunnel. Take a look at some of my handy CAD (carboard aided design) work below:

Ordered a mechanical oil pressure gauge kit from ISSPRO as the stock electrical gauge is pretty useless.

Road test photo:

 

[seatosummit]

Long time no post, sorry about that! Been out of the country for work off and on for better part of a year.

In any case, now back on the project of getting the LC squared away.

Latest question is why the poor fuel economy, low power and excessive black smoke? Things I have attempted as a means of solving:

• injector nozzle rebuilt (minimal difference)
• valve clearance adjustment (minimal difference)
• backed out max fuel screw two full turns; now has 4 threads showing to the right side of the nut (this made a large difference, though experienced a major drop in torque and hp, even still, smokes under highway load). I should say that my injector pump max fuel setting on my old engine was showing 6 threads also when it was operational, so this makes me think that is a fairly average value, 4 is "underfueled"
• changed all filters (air, fuel, oil)
• ran 2 cans of diesel purge (no difference)

This leads me to suspect it has something to do with my injection timing. I have never adjusted timing on a diesel before, and to be quite honest it scares the hell out of me! I don't to make an adjustment that wreaks havoc on other systems.

Does any one have any additional input as to what my causing the symptoms, and/or if there is consensus that timing needs to be adjusted, is this something that can be done without the described SST gauge in the FSM, or do I need to take it to a pro?

Thanks a lot!

Austin

Attaching some photos from a trip I made a couple months ago up to Big Sur--truck did great even with 2WD (finally sourced a rear output shaft from a 60 series to swap into the front of my truck).

 

[Brewsterfire]

You might be best off taking it to a diesel shop that can set up your injection pump.
I had mine sent away to be set up, guess I will find out how well it was done prior to my rebuild.
There are a million parts in there.

Cheers

 

[seatosummit]

Called around pretty extensively yesterday, and most thought that it was unlikely to be the IP timing, as the pump has never been removed, and the notch mark on the casing align perfectly with the corresponding mark on the block. I am going to swap out the diaphragm and play around with the max fuel setting to see if I can find the sweet spot.

 

[seatosummit]

Made the drive from Santa Barbara to Tahoe with no major issues. The black smoke issue wasn't major unless I stepped on it, though fuel economy was poor (18 MPG). Found the 5th gear pretty nice in the flats of California's central valley.

I will be pulling off the top in the next few weeks to begin restoration of the rain gutters which have pretty much been turned to swiss cheese at this point.

 

[Brewsterfire]

Did you replace the diaphragm? Or adjust the max fuel setting?

Just curious!

 

[seatosummit]

I replaced the diaphragm, but I likely didn't need to, as it passed both the "suck" test proposed by lostmarbles somewhere on this forum, and the more accurate vacuum test with an actual gauge. The real benefit came out of adjusting the max fuel setting. Bummer is the new fuel setting has it feeling pretty gutless as compared to my previous 3B.