First time pulling tranny

[still learn'n]

I am pulling a tranny on a truck for the first time ever the clutch has an issue it's on a 99 Mack RD688S. Any pointers or is there something else to engine, clutch or tranny I should do?

I have a pit in shop I'm doing it over that I put a track or rail in when we did the concrete work and i already made a lift to put in a diff on another truck and was planning on adapting it to pull the tranny so if I can lower the tranny low enough will I be able to pull it with out pulling the shift lever? The shaft is on the tranny and then goes into the clutch right? So how long is that shaft? As thick as the clutch?

Do you just get a clutch from any truck parts supplier or is there one that's recommended?

 

[Junkyard]

You'll need to pull the shifter. Don't lose the little springs under the cover. I'm not sure which shaft you're referring to. Pull shifter, drop the driveline, mark and remove air lines, unhook speedo, cooler lines if equipped. Remove clutch linkage, remove rear crossmember if equipped. Support on jack, remove bellhosing bolts. The shaft running through the bellhousing that operates the throwout bearing should turn enough as you come out to disengage from the throwout bearing.

Clutch itself is HEAVY. You'll need something to help support it. As far as sources for the clutch you can go dealer, parts house, clutch ad brake rebuilder etc.

 

[crane operator]

I've never done one from a pit, I've got a antique version of this walker jack, I just ratchet strap the transmission to the plate with a block of wood for the slope of the bottom of the transmission (eaton). If its a mack transmission, those have a real V bottom, and you may have to make a funky bracket / cradle. You'll need at least 10" or so of rearward movement to clear the clutch.

Other than that- just what junkyard said- he types faster than me.

 

[still learn'n]

I can take pics in the morning but this tranny has a flat bottom besides the pto.

So to pull the shifter pull the 4 bolts and watch for the springs and it will come out? Does it slip into a ball or slot or is there a way it has to come in or out?

 

[Junkyard]

I can take pics in the morning but this tranny has a flat bottom besides the pto.

So to pull the shifter pull the 4 bolts and watch for the springs and it will come out? Does it slip into a ball or slot or is there a way it has to come in or out?

There's an obvious spot for the end of the shifter you'll see once you pull it. It's hard to get it together wrong, but not impossible. Biggest thing on detent springs is depending on whether or not the gasket comes with shift tower. It's not like they're huge and shoot you through the roof, just pesky little buggars that are easy to lose. It'll lift straight up more or less. Depending on which trans you may have a couple small air lines to unhook. Be sure to mark them or take pics. It'll save ya later!

 

[Jonas302]

I like to put it in gear before pulling the shifter it makes it easier to turn the output shaft to align the splines going back in the shifter will go back in just fine I make a cover plate out of plywood or cardboard and bolt it back over the hole
Dont be afraid to pull up the floor plate around the shifter it makes it a lot easier than working all from the bottom although I have never done one standing up
you will need a pilot bearing
get a grease drop hose kit if your truck doesnt already have it on the throwout bearing so you dont have to push the pedal to grease
You will need a clutch brake
also a clutch line up tool
good time to change trans oil
All can be got a good truck shop sometimes the Mack dealer is quite competitive on price and less chance of the wrong parts

 

[RZucker]

Myself, if you don't have a lot of room to move the trans back, I like to unbolt the clutch an push it back on the input shaft and pull it off a piece at a time after lowering the trans, whole lot easier on your back. Then just stack the new clutch back on the shaft and bolt it up after the trans is back in the truck.

 

[Junkyard]

Myself, if you don't have a lot of room to move the trans back, I like to unbolt the clutch an push it back on the input shaft and pull it off a piece at a time after lowering the trans, whole lot easier on your back. Then just stack the new clutch back on the shaft and bolt it up after the trans is back in the truck.

There are times I do the same. Depends on what it's in etc. I've built all kinds of tools over the years for lifting and alignment etc. Even have a vast selection of covers for shifters and PTO's as well as old input shafts.

 

[RZucker]

There are times I do the same. Depends on what it's in etc. I've built all kinds of tools over the years for lifting and alignment etc. Even have a vast selection of covers for shifters and PTO's as well as old input shafts.

Yep, really depends on the case at hand.

 

[Junkyard]

Yep, really depends on the case at hand.

First timer leaving it on the trans is probably the best bet. Going back together too.

 

[Truck Shop]

Like said above remove the eight clutch bolts going through the inspection cover opening and drop the clutch with the transmission. You will only have pull the trans back
three inches to gain clearance. Install in reverse. Are the rear engine mounts on the transmission bell or the engine flywheel housing?

Truck Shop

 

[bam1968]

We have the flywheel turned every time we put a new clutch in a truck. I don't know if it is common practice to have it turned every time. I can remember two times that I didn't have the flywheel turned and both times the trannys had to come back out and have them turned. Just my $.02

 

[still learn'n]

The rear mounts are on the tranny. I kinda was thinking I could just run a 2" rachet strap under the rear of the engine or is there a better way?

 

[still learn'n]

Here is some pictures it is an Eaton and I believe it's a 9 speed

 

[Truck Shop]

Personally I would be spooked doing that job in a pit but that's just me. That looks like a RTX series 9 or 10 speed, it's an early case because it has the large fill plug.
You will have to jack that engine to clear the rear mounts then safety chain it from one rail to another, unless there is a overhead hoist directly over that pit.

Truck Shop

 

[John C.]

Man, I sure don't miss doing that stuff anymore!

 

[Tenwheeler]

I just would not do that over the pit. I prefer to do those on a slab with the front tires on 6X6's. Bottle jack with a 2X4 under the flywheel housing. Block between the frame and the engine on both sides after you jack it up. Put the jack up under the PTO but centered under the transmission. Bolt a piece of steel to the upper RH PTO cover bolts and a piece of big angle, like a frame rail section, to the jack. Then weld them together.
In a jam I have cut a piece pipe a bit wider than the frame. It should be 2 1/2- 3 inches in diameter. Center it above the transmission. Remove the top plate bolts in front and in back of the pipe on both sides. Cut two pieces of 1/4 - 3/16? inch chain just long enough to go over the pipe and about 1 1/2 inches above the bolt holes. Install bolts with flat washers just long enough to start in the threads good. Then screw all four of them in equally about one inch. Use channel locks on the pipe moving the transmission while rolling the pipe. Never saw one fall but never never ever get under it.
You may thank that is scary but I will take it over your pit deal any day.

 

[Truck Shop]

My shop partner and started this last Monday morning on a Series 60 rear structure reseal. We R & R-ed the left fuel tank, air tank, transmission, flywheel, oil pan
and flywheel housing/rear structure. Replaced rear main seal resealed the housing to block, replaced out put seal on trans, clutch, clutch brake and pilot, installed
surfaced flywheel and replaced rear mounts and flex pipe from turbo. Then we installed a reman Eaton DS 404 front drive plus two torque arms. Steam cleaned
everything while it was out.----------We finished yesterday at 1:00 PM. I start work at 6:00 AM. Plus Serviced Four tractors and two trailer in that time span.
Including draining a fuel tank and removing it plus the air tank then the transmission that only takes us a little over 1 hr. Working on creepers.

Truck Shop

 

[John C.]

Truck Shop; that is real nice and professional work but in my case doing one, maybe two clutches every two years makes the job new each time. Got to remember how I lifted it last time, where are the eye bolts I made, where did the pilot shaft go, oh I forgot I have to fix all the air lines again before I get it back together and the dang 966B is broke again and another dump truck died in the pit and now the boss wants a brake job done on his pickup and the parts just showed up for the D8H and they just stranded the ejector line on the Letourneau scraper and the pump on the wash plant quit putting out water and on and on and on and on infinitum.

 

[Truck Shop]

Well that's when I tell everyone to take a number or get in line. I deal with 52 company tractors and 90 company trailers.

Truck Shop