Rob Posted February 20, 2020 Share Posted February 20, 2020 The long and short of your problem is the incorrect rear engine mounts are most likely installed. I suspect when the transmission was changed by the prior owner it was a used unit pulled from an eastern R model with a splayed frame and installed into your straight frame rail truck without swapping the mounts from the original transmission. If you look at the mounts side by side it is easy to ascertain the difference and see the outward offset, (front hole) to the splayed frame mounts, where the straight frame mounts are in a parallel plane to the transmission case. Just a casual glance and most didn't see any difference but if you install as this scenario, the engine is back about 5/8" usually. There are four different sets of insulators available for the R series I remember and believe it or not using the incorrect insulators, you can get the retention bolts installed. Many did exactly this during the late 1970's into the 80's and various methods to correct for it were attempted including shimming frame mounts to offset the mounting location. Think about it for a minute: the bolts go into the holes and these bolts are equidistant from the frame rail flange edge as shown here on my R795S left frame rail: Right frame rail: The rear engine mounts on the eastern trucks are in the splay area of the frame which is why the offset. If you look at the fasteners and were to lay a rule from them to the edge of the frame rail flange, they would measure close, (within manufacturing tolerances). The same applies to an RL series shown here: Left side: Right side: As can be seen from the photos the fasteners are just about in the same parallel plane whether a straight rail or splayed rail frame. I suspect your transmission was swapped without regard to any of the mounts being slightly different. The inexperienced eye would probably not see it in a hurried atmosphere and it could have been easily thought they are the same. There is no difference in the rear engine mounts mounting pattern of the TRL-107, or TRDL-107 or any of their variants. The only real difference is the length of the transmission rear tail housing. If going from a five speed to a six speed transmission as example, the driveline needs shortened about 6.5 inches. Conversely if from a six speed to a five speed as the 685 series was offered. Bottom line I feel is you are going to need to round up the correct rear engine mounts, or manufacture your own to correct your problems. I've done them in the past as they were "hen's teeth" to find all those years ago used. Hopefully the mounts on the frame are original to the truck or another chapter opens. Not a hard hill to surmount but one that does need climbed. Rob 2 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/60866-mack-rl-question/page/3/#findComment-443268 Share on other sites More sharing options...
Lmackattack Posted February 20, 2020 Share Posted February 20, 2020 Now that we know you have a RL685LST we know the truck should have had a mack trans installed from the factory and the frame is set up for mack mounts. Rob is spot on with his notes of how eastern and Western R models will have different rear mounts due to the difference in frames. The RL/RL685 trans mounts will not be the same as a Eastern R685. I suspect the current RL frame mount is going to be correct and the trans side of things is of a eastern Mack as you noted the trans is not original to the truck. the untrained eye may have not seen the difference in mounts and was easily overlooked when installed. Rob provided us with photos that you can clearly see what is what between east and west coast R model mounts. Quote Link to comment https://www.bigmacktrucks.com/topic/60866-mack-rl-question/page/3/#findComment-443280 Share on other sites More sharing options...
Ditchdiggerjcf Posted February 20, 2020 Author Share Posted February 20, 2020 Well done sirs. I will hunt some west coast mounts. Wish me luck. Quote Link to comment https://www.bigmacktrucks.com/topic/60866-mack-rl-question/page/3/#findComment-443282 Share on other sites More sharing options...
Rob Posted February 20, 2020 Share Posted February 20, 2020 9 hours ago, Ditchdiggerjcf said: Well done sirs. I will hunt some west coast mounts. Wish me luck. They are out there but getting scarce. I made the last set I'd needed to install a Fuller into an RL-685: They don't have to be anything special, just ensure enough strength, and your driveline angle is correct, as these directly support that. 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/60866-mack-rl-question/page/3/#findComment-443303 Share on other sites More sharing options...
Ditchdiggerjcf Posted February 20, 2020 Author Share Posted February 20, 2020 Those look awfully flimsy compared to the factory jobs. Mine are still working trucks and have to be able to handle rough duty. Quote Link to comment https://www.bigmacktrucks.com/topic/60866-mack-rl-question/page/3/#findComment-443317 Share on other sites More sharing options...
Rob Posted February 20, 2020 Share Posted February 20, 2020 Not flimsy at all being 3/4" plate gussetted with 1/2" strip.. idea was directly copied from factory mounts in another mack with a Roadranger trans. Truck still works every day during planting and harvest running well over legal limits. 2 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/60866-mack-rl-question/page/3/#findComment-443346 Share on other sites More sharing options...
Rob Posted February 21, 2020 Share Posted February 21, 2020 I had repowered that truck with a 300+ engine and installed this 16 series 13 speed replacing the original TRXL-107 which was worn in, and out. The original ENDT-675 engine was rebuilt complete, and installed into one of their sprayer trucks which was an R-685 with a hole in the block. The original TRXL-107 remained in that chassis. Not many around here really favor the old two stick transmissions any longer and I've been asked to convert this one over to a Fuller. 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/60866-mack-rl-question/page/3/#findComment-443395 Share on other sites More sharing options...
Ditchdiggerjcf Posted February 21, 2020 Author Share Posted February 21, 2020 I have managed to scrounge up a few 2 sticks. I like em for the work we do. The multiple pto speeds and multi reverse speeds is awesome. Nevermind the fact that they are tough as boot leather. Quote Link to comment https://www.bigmacktrucks.com/topic/60866-mack-rl-question/page/3/#findComment-443410 Share on other sites More sharing options...
880joe Posted February 21, 2020 Share Posted February 21, 2020 So are you needing transmission mounts from an RL with a 2 stick 6 speed? Quote Link to comment https://www.bigmacktrucks.com/topic/60866-mack-rl-question/page/3/#findComment-443426 Share on other sites More sharing options...
Rob Posted February 21, 2020 Share Posted February 21, 2020 Another set of OEM Mack rear engine mounts removed from an R model and given to me by one of my vendors after they sold the Fuller transmission from the truck. I also have the frame brackets too. These are fabricated with 1/2" material. 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/60866-mack-rl-question/page/3/#findComment-443436 Share on other sites More sharing options...
Rob Posted February 21, 2020 Share Posted February 21, 2020 If'n you get to needing another two stick six speed, the one in my R-795S is going to be replaced with a 12 speed Mack sometime in the future. Nothing wrong with the trans and it is the TRDL-1071 with 23:1 reduction in the lowest gear. 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/60866-mack-rl-question/page/3/#findComment-443438 Share on other sites More sharing options...
Ditchdiggerjcf Posted February 22, 2020 Author Share Posted February 22, 2020 7 hours ago, 880joe said: So are you needing transmission mounts from an RL with a 2 stick 6 speed? Yep Quote Link to comment https://www.bigmacktrucks.com/topic/60866-mack-rl-question/page/3/#findComment-443474 Share on other sites More sharing options...
Ditchdiggerjcf Posted February 22, 2020 Author Share Posted February 22, 2020 6 hours ago, Rob said: If'n you get to needing another two stick six speed, the one in my R-795S is going to be replaced with a 12 speed Mack sometime in the future. Nothing wrong with the trans and it is the TRDL-1071 with 23:1 reduction in the lowest gear. I would like to have it. You already have a 12? Quote Link to comment https://www.bigmacktrucks.com/topic/60866-mack-rl-question/page/3/#findComment-443475 Share on other sites More sharing options...
Ditchdiggerjcf Posted February 22, 2020 Author Share Posted February 22, 2020 I got these today. They look like they should work but I'm not positive they are the right ones. I saw at least 4 different rear mount styles today. Crazy. Quote Link to comment https://www.bigmacktrucks.com/topic/60866-mack-rl-question/page/3/#findComment-443477 Share on other sites More sharing options...
Rob Posted February 22, 2020 Share Posted February 22, 2020 (edited) 9 minutes ago, Ditchdiggerjcf said: I would like to have it. You already have a 12? Yes I do have a 12 speed already. It will probably be late spring before I'm ready to pull the truck down however as I've got a lot of projects to get out of the way. Do you have any numbers from those mounts you have? I can see some on your photo but cannot effectively make it out. I can pretty easily see the mounts in my RL out back I put photos up from. Edited February 22, 2020 by 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/60866-mack-rl-question/page/3/#findComment-443478 Share on other sites More sharing options...
Ditchdiggerjcf Posted February 22, 2020 Author Share Posted February 22, 2020 Your RL a 600 or 700? Quote Link to comment https://www.bigmacktrucks.com/topic/60866-mack-rl-question/page/3/#findComment-443480 Share on other sites More sharing options...
Rob Posted February 22, 2020 Share Posted February 22, 2020 RL 797 but I have access to an RL600 to look at. I think it's an RL-686 w/tip turbin engine. 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/60866-mack-rl-question/page/3/#findComment-443481 Share on other sites More sharing options...
Ditchdiggerjcf Posted February 22, 2020 Author Share Posted February 22, 2020 The 686 mounts should be the same. I have seen some from a 700. They look different. They have offset. Quote Link to comment https://www.bigmacktrucks.com/topic/60866-mack-rl-question/page/3/#findComment-443482 Share on other sites More sharing options...
Rob Posted February 22, 2020 Share Posted February 22, 2020 yes, that is correct. 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/60866-mack-rl-question/page/3/#findComment-443497 Share on other sites More sharing options...
Ditchdiggerjcf Posted February 22, 2020 Author Share Posted February 22, 2020 When will you see the RL600. Quote Link to comment https://www.bigmacktrucks.com/topic/60866-mack-rl-question/page/3/#findComment-443503 Share on other sites More sharing options...
Rob Posted February 22, 2020 Share Posted February 22, 2020 I can get by there next week. It's only about 40 miles distant and I need to look at a job over that way. 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/60866-mack-rl-question/page/3/#findComment-443504 Share on other sites More sharing options...
Rob Posted February 22, 2020 Share Posted February 22, 2020 Meanwhile with your serial number I'll have it run at my dealer to see what that truck was built with. Parts guy I've been friendly with over 35 years only works a couple days a week any longer so may take a while to get information back. Maybe one of the former parts persons on the site can post up that information rather than reinvent the wheel? 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/60866-mack-rl-question/page/3/#findComment-443505 Share on other sites More sharing options...
Ditchdiggerjcf Posted February 22, 2020 Author Share Posted February 22, 2020 Doesn't look like that is going to happen. Quote Link to comment https://www.bigmacktrucks.com/topic/60866-mack-rl-question/page/3/#findComment-443506 Share on other sites More sharing options...
Ditchdiggerjcf Posted February 23, 2020 Author Share Posted February 23, 2020 (edited) 21 hours ago, Ditchdiggerjcf said: I got these today. They look like they should work but I'm not positive they are the right ones. I saw at least 4 different rear mount styles today. Crazy. Part # visible. Anybody know the application? Edited February 23, 2020 by Ditchdiggerjcf Quote Link to comment https://www.bigmacktrucks.com/topic/60866-mack-rl-question/page/3/#findComment-443528 Share on other sites More sharing options...
Rob Posted February 28, 2020 Share Posted February 28, 2020 Truck was built with following part numbers: Left rear engine mount on trans: 158GB49326T2 Right rear engine mount on trans: 158GB49325T2 These numbers should be on the parts you need. I can't read your numbers from the photos on my phone. 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/60866-mack-rl-question/page/3/#findComment-443963 Share on other sites More sharing options...
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