Rob Posted January 31, 2012 Share Posted January 31, 2012 Hey there, the 2100 series transmission in the R model is very difficult to shift in the gears. You really have to yank the shift handle to switch gears. It is nothing like a Fuller, or the older Mack transmissions I havce in any truck. Tonight I pulled the floor panel and removed the shifter and tower and the forks and blocks are very difficult to move with a screwdriver. I don't see anything wrong through the opening but something is definately binding. There is no way to remove the top cover and forks from the trans with it in the truck so I know it has to come out which I'll do prolly next week.Anybody got any ideas what could be the cause? It was easy to shift a couple months ago. The oil is full with Synthetic, and the trans is clean internally. Nothing is binding and grinding like a broken spring and displaced detent balls.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/ Share on other sites More sharing options...
David Posted January 31, 2012 Share Posted January 31, 2012 "It was easy to shift a couple months ago"If the only thing that's changed is the temperature, try getting it warmed up. Quote Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100460 Share on other sites More sharing options...
slpwlker Posted January 31, 2012 Share Posted January 31, 2012 Sounds like it needs to be warmed up. Quote Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100464 Share on other sites More sharing options...
Rob Posted January 31, 2012 Author Share Posted January 31, 2012 Not a heat related problem. I was dragging my drop deck around with a truck on it. No difference cold or hot. You have to yank it out of year with such force you will pass through the neutral gate and grind on the next gear from the force.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100466 Share on other sites More sharing options...
David Posted January 31, 2012 Share Posted January 31, 2012 Is the PTO engaged? Just driving around the yard won't warm it up enough. Quote Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100468 Share on other sites More sharing options...
Rob Posted January 31, 2012 Author Share Posted January 31, 2012 Is the PTO engaged? Just driving around the yard won't warm it up enough. No the PTO is out/disengaged. I drove about 30 miles today loaded at all different speeds. No out of ordinary noise, no vibration, nothing seems amis running on the road. Just hard to up, or downshift. Rob 1 Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100469 Share on other sites More sharing options...
slpwlker Posted January 31, 2012 Share Posted January 31, 2012 How heavy and what was the outside temp? When it is cold out it takes my trans a long time to warm up unless I am heavy. Even then it takes a little while. Does it have a dash mount Power Divider. Almost sounds like the rears are locked. That makes shifting a bitch if nothing is wrong with the trans Quote Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100501 Share on other sites More sharing options...
Rob Posted January 31, 2012 Author Share Posted January 31, 2012 How heavy and what was the outside temp? When it is cold out it takes my trans a long time to warm up unless I am heavy. Even then it takes a little while. Does it have a dash mount Power Divider. Almost sounds like the rears are locked. That makes shifting a bitch if nothing is wrong with the transI had a 20,000# truck on the 13,000# drop deck so not real heavy. It is difficult to pull it into any gear sitting still This feel like the shift rails are extremely rusty and trying to slide them through the bores. It is like something such as a sliding clutch gear is binding on it's shaft? This doesn't feel like there is mechanical bind as it doesn't matter if the truck is moving, or sitting still, engine running or not. I can spin the pto shaft by hand. A me and Jaime, (helper) can shove the truck by hand on the flat floor. Something is definately binding and it feels like something is not lubricated, or lubricating.I can't rememove the top cover with the trans in the truck so I'm thinking the next step is to pull it out to get a good look into the top and evaluate the rails, forks, springs and detent balls. I'm hoping the main shaft is not twisted but I don't know how that would have happened as I've not used the truck except to haul what I've mentioned.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100504 Share on other sites More sharing options...
Rob Posted February 1, 2012 Author Share Posted February 1, 2012 Tonight I was able to remove the bolts securing the top cover and hold it up high enough to get the shift forks to clear the sliding clutches. With the trans remaining in the truck there is not enough clearance to remove the top cover. Using a long screwdriver to push and pull the sliding clutch gears takes a considerable amount of force to make them move. Using a bright flashlight it is clear to see distortion to the splines the sliding clutches ride and bear upon.I'll price a rebuild kit for this but may also look to swap to a nine speed instead. This one has a bit too fast of reverse and low speed.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100583 Share on other sites More sharing options...
Lmackattack Posted February 1, 2012 Share Posted February 1, 2012 On my B model the aux stick was hard to move but the main was louse. It ended up that there was so much crud built up around where the shifter moved that it was always hard to move. took alot of lube and movement to get it louse again. I did this all with the floor boards out of the cab. It was a PITA but it was better after a few hours of moving them. all the macks I drove were a little stiff in the cold and once warm they were back to normal. Also if the shift rails are not getting splashed lube it will just compound the issues. the oil needs to get thin and warm to properly lube them. if water got in the trans it will just make a mucky mess of the rails and dirt will stick to them. Only other thing could be that the shift rail is bent? or the shaft that the gears slide on are bent or was overheated. all of wich needs a tear down to inspect..trent Quote Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100587 Share on other sites More sharing options...
Rob Posted February 1, 2012 Author Share Posted February 1, 2012 What are the low, and reverse gear ratios in this T2100 transmission? What would be the best unit to replace it with to haul dump trailer for seed and rock into and out of dirt fields? Don't know if I want to rebuild this one or not as it has too fast of reverse for my liking. Thanks, Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100608 Share on other sites More sharing options...
David Posted February 1, 2012 Share Posted February 1, 2012 Low is 8.52Rev is 11.76Mack always advertised the 10sp as an on road trans and the 9sp as an on/off road. Quote Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100613 Share on other sites More sharing options...
Rob Posted February 1, 2012 Author Share Posted February 1, 2012 Low is 8.52Rev is 11.76Mack always advertised the 10sp as an on road trans and the 9sp as an on/off road.Hi David and thanks. I was thinking by the way this this pulls from a stop it was in the high eights for reduction. Everything else I have is in the 11.5 or lower so don't think I'll rebuild this one for working in fields. I can't argue for free as this is the truck that was left to me in the estate. It has always been more difficult to shift than the others but this past week hauling my trailer it became unbearable to live with. I want to use the truck for some hauling and a customer is willing to let me use their dump trailer at will around the shop.Last night when I got the top cover popped loose, I propped it up with tapered builders shims and blocks of wood to keep it elevated. With sliding the center clutch forward exposing the splines on the mainshaft, there is about 1/8" twist to the splines; a dead giveaway there are problems internally. I have the two stick six speed in "Project R-12" that is the TRXL-1071 and has the 23:1 reduction. I may use it as it won't do so well behind the Detroit engine. I'll do some length measuring tonight for that idea. Otherwise I'll need another trans, driveline, etc.Would you know if the nine speed is the same length as the 10 speed currently installed? If so that may be the way to go. What series of nine speed would you recommend?Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100615 Share on other sites More sharing options...
MACKTRUCKS4 Posted February 1, 2012 Share Posted February 1, 2012 My superliner had a 9sp. in it when I bought it. Pulled it out and replaced it with a 12sp. Backing off road with lowboy, dump trailer and water tanker required a lower reverse. Have all I need with the 12sp. Quote Live every day like it's your last, because one of these days, it will be. Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100616 Share on other sites More sharing options...
maxidyne237 Posted February 1, 2012 Share Posted February 1, 2012 the 2090's and 2010's were famous for twisting the mainshaft when abused. A good 2090 with an updated syncro is not a bad transmission for what you are trying to do. Quote Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100621 Share on other sites More sharing options...
Rob Posted February 1, 2012 Author Share Posted February 1, 2012 the 2090's and 2010's were famous for twisting the mainshaft when abused. A good 2090 with an updated syncro is not a bad transmission for what you are trying to do.Thanks Chris, is the 2090 the same length as a 2100?Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100622 Share on other sites More sharing options...
maxidyne237 Posted February 1, 2012 Share Posted February 1, 2012 Welcome Rob. I believe it is the exact same case just with different gearing. The Mack service manual even covered both transmissions in one volume with one overhaul procedure. Quote Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100623 Share on other sites More sharing options...
David Posted February 1, 2012 Share Posted February 1, 2012 Don't know on the length. We have two with T2090's. 4.42 with 22.5" and 4.64 with 24.5". That's about a 5% difference in gears and about a 5% difference in tires so both trucks run about 75 mph under 2000 rpm. And both are good coming out of a hole loaded. Quote Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100625 Share on other sites More sharing options...
Rob Posted February 1, 2012 Author Share Posted February 1, 2012 Thanks guys, this truck is on 22.5 rubber and 4.17 ratios. It was built with a straight five speed and obviously a road tractor.the deceased former owner had this 10 speed installed as the five speed was just to wide spread in the pattern. I think it can be used with these rears if careful on things?Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100631 Share on other sites More sharing options...
Lmackattack Posted February 1, 2012 Share Posted February 1, 2012 If I recal a 9 speed with 4.17 will be too fast in the mud. I think the 9 speed has a much taller gearing as it was intended to be used with slower rear ends. The idea was to have a fast drive line speed and reduce stress on the gears. this was good and bad..good because it was not as harsh on the gears but bad because the over drive gearing of the transmisson caused more roatinal mass and thus you need more HP to keep it going in the top gears. most of the trucks I drove with the 9 speed that were built for the mud had 5.02 or slower.the 12 speed will do everthing you will ever want. 4.17 was a common gearing with the 12 because it was very slow in both forward and reverse and you still had a good top overdrive gear to get home. Quote Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100649 Share on other sites More sharing options...
Superdog Posted February 1, 2012 Share Posted February 1, 2012 I have a T2090 in my '87 Superliner,4:17 rears,lo pro 24.5's which would be the same as 11R22.5 ,never had any problems pulling loads out of farm fields or muddy lots.Gives you nice road speed too.A T2090 has a .71 overdrive,where a T2100 is .77 and a TRTXL1070a 12 speed is .78 Quote Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100654 Share on other sites More sharing options...
maxidyne237 Posted February 2, 2012 Share Posted February 2, 2012 I have a T2090 in my '87 Superliner,4:17 rears,lo pro 24.5's which would be the same as 11R22.5 ,never had any problems pulling loads out of farm fields or muddy lots.Gives you nice road speed too.A T2090 has a .71 overdrive,where a T2100 is .77 and a TRTXL1070a 12 speed is .78I have to agree. Have driven plenty of miles with 4.17s 11r22.5 rubber and 2090 pulling dump trailer on and off road. I felt that low was low enough for a tractor that isnt climbing out of basements, and would do 75 mph comfortably. Quote Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100739 Share on other sites More sharing options...
maxidyne237 Posted February 2, 2012 Share Posted February 2, 2012 Mike is that 2090 in the cummins powered truck? Quote Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100741 Share on other sites More sharing options...
Lmackattack Posted February 2, 2012 Share Posted February 2, 2012 The 2090s I have driven were just fine for on/off road flat land dumping and such but if it was used on site in the muck or hauling 90K in the soft clay I always thought it needed a lower gear. Thats why I liked the low low that the 6 and 12 speeds had and more reverse gears!. To me if the truck is to be used off road at all you need that extream low gear for the times that they sink in the clay.Also there were 2 versions of the 2090 if I recall right... I think there was one built with a lower 1st gear intended for more off road use...Would have to check My 9 speed book manual to be 100% sure oin that.... Quote Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100748 Share on other sites More sharing options...
Superdog Posted February 2, 2012 Share Posted February 2, 2012 Mike is that 2090 in the cummins powered truck?No,it has a 13 speed double over Fuller,the 2090 is in my '87 Liberty. Quote Link to comment https://www.bigmacktrucks.com/topic/22970-mack-2100-series-transmission/#findComment-100762 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.