DieselDog5.9 Posted April 20, 2020 Author Share Posted April 20, 2020 Low Range Clutch Smoked. Quote Link to comment Share on other sites More sharing options...
DieselDog5.9 Posted April 20, 2020 Author Share Posted April 20, 2020 Broken Shit Quote Link to comment Share on other sites More sharing options...
DieselDog5.9 Posted April 20, 2020 Author Share Posted April 20, 2020 Snap ring broken in outer groove. Quote Link to comment Share on other sites More sharing options...
DieselDog5.9 Posted April 20, 2020 Author Share Posted April 20, 2020 These allen bolts were loose, took off with my fingers, looks like they hit the plate. Quote Link to comment Share on other sites More sharing options...
DieselDog5.9 Posted April 20, 2020 Author Share Posted April 20, 2020 I always thought Mack Transmissions were wicked rugged, 6 speed and 12 speed especially, figured 18 speed would be similar, didn't think you could break one. Quote Link to comment Share on other sites More sharing options...
Mack Technician Posted April 20, 2020 Share Posted April 20, 2020 Synchro is the Achilles’ heel of that trans. The guy who trained me use to say they were also overly massive...to a fault. He believed the size of it gave it too much fly weight. Even a subtle driveline vibration ends badly since it’s weighty and resists counter-movement. A Fuller synchro is microscopic in comparison. Mack stole a little from Fuller on the T300’s, they should have stole the synchro. 1 Quote Link to comment Share on other sites More sharing options...
fjh Posted April 20, 2020 Share Posted April 20, 2020 (edited) 11 hours ago, DieselDog5.9 said: I always thought Mack Transmissions were wicked rugged, 6 speed and 12 speed especially, figured 18 speed would be similar, didn't think you could break one. You don't often see the plate carrier busted up that bad ! usually the clutch and reaction discs are toasted ! was the yoke bolt tight? Yup this is why Daves comment is somewhat valid! The price gouge on those is your next hurdle! Volvo wants you to buy a new truck So Those parts will not be cheap! That same failure on a fuller When it does happen which is not that often ! will cost a 1/3 or less than the Mack parts! They are going to ask you if you would like it dri or lubricated BEND OVER BUD! . Check out PAI for part pricing! That being said These tranys have put food on my table for a lot of years ! Just like injector cups will make work for the new generation of guys for a few more years!! Edited April 20, 2020 by fjh Quote Link to comment Share on other sites More sharing options...
DieselDog5.9 Posted April 20, 2020 Author Share Posted April 20, 2020 The owner of the truck insists on Mack parts, and I think the down time for him is the bigger cost right now, tore it apart saturday, put parts order in this morning, could have parts Tuesday, fingers crossed. My fear is forgetting 1 oring that will hold up the whole job. Judging by your comment puchasing the injector cup tools for C15 last month was a good investment. Quote Link to comment Share on other sites More sharing options...
DieselDog5.9 Posted April 21, 2020 Author Share Posted April 21, 2020 First I would like to say engineers are stupid, whoever designed this should just quite, and go sell kites at the beach. Second is this normal? The plate is offset from some of the pins, says nothing in the service manual and I have twisted this plate until i was blue in the face, figure it must twist when shifted. Bought the "Update Kit" with new synchroniser plate and gears. Quote Link to comment Share on other sites More sharing options...
Mack Technician Posted April 22, 2020 Share Posted April 22, 2020 Dave has officially taken you under his wing and put you in his will. I think the thing’s fascinating. You scratch your head on some of Mack’s stuff and have a hard time picturing the dynamics. A perfect example is the peanut wedges rolling between the eccentric cams of a power divider. Alien concept. Offset is normal. When rotating it makes a resistant twist-in engagement. It’s part of the action that loads the clutches against the plates to cause friction meshing. 1 Quote Link to comment Share on other sites More sharing options...
fjh Posted April 22, 2020 Share Posted April 22, 2020 The offset and Taper helps align the teeth with friction when the shift is make your fuller trans has the same set up however much simpler in design and Less complicated! And way Cheaper to Repair IF it fails!! Make sure all the pieces marked R are faceing Rear and your good to go! That set up sed to be offered as a pre assembled unit just drop the discs and seperators in and go! if I remember right! Quote Link to comment Share on other sites More sharing options...
fjh Posted April 22, 2020 Share Posted April 22, 2020 (edited) 3 minutes ago, fjh said: The offset and Taper helps align the teeth with friction when the shift is make your fuller trans has the same set up however much simpler in design and Less complicated! And way Cheaper to Repair IF it fails!! Make sure all the pieces marked R are faceing Rear and your good to go! That set up used to be offered as a pre assembled unit just drop the discs and seperators in and go! if I remember right! Try to make sure you install your snap rings with the sharp edge to the rear rounded edge facing the bearing! Edited April 22, 2020 by fjh Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.