CDNFlatTrackFreak Posted January 9, 2020 Share Posted January 9, 2020 Hey folks new here. As stated I have a 1998 Mack RB688s with the Eaton 8LL. Wondering if anyone has had to replace there reverse switch on transmission? I've been told it's under the shifter boot and accessible from the cab. Is this true? Have flickering reverse lights as well as my backup alarm flickers in sync with lights. Seems like a simple fix once I know where the actual switch is? Any help would be greatly appreciated! Sent from my SM-G960W using Tapatalk Quote Link to comment https://www.bigmacktrucks.com/topic/60471-1998-mack-rb688s-tri-axle-dump-reverse-switch-location-on-tranny/ Share on other sites More sharing options...
alex g Posted January 9, 2020 Share Posted January 9, 2020 Can't help you on your question but truck looks good. I'm assuming by your name your from Canada. Whereabouts you located? Quote Link to comment https://www.bigmacktrucks.com/topic/60471-1998-mack-rb688s-tri-axle-dump-reverse-switch-location-on-tranny/#findComment-439875 Share on other sites More sharing options...
BigBlue688s Posted January 9, 2020 Share Posted January 9, 2020 9 minutes ago, alex g said: Can't help you on your question but truck looks good. I'm assuming by your name your from Canada. Whereabouts you located? Thanks man we have had it for about 6 months now. Got it from a reputable paving company known for its upkeep, and very minimal winter driving. They bought 3 of these brand new. They still have 1 and sold 2. From Niagara Region, Ontario. I try my best to keep her pretty and maintained. This is the first real dump truck we have. I do most the minor upkeep myself. If it's out of my comfort zone It goes to the mechanic we use, but we dont have our own she runs monday to Friday for a construction outfit here. I imagine the things she has seen since coming on board with us just boggles her mind. She has been a great truck though! Are you a fellow canuck? Quote Link to comment https://www.bigmacktrucks.com/topic/60471-1998-mack-rb688s-tri-axle-dump-reverse-switch-location-on-tranny/#findComment-439876 Share on other sites More sharing options...
alex g Posted January 9, 2020 Share Posted January 9, 2020 Yes I'm from Dunnville. I'm assuming that was a circle P truck. I think I've seen you around the falls with that truck. Can't remember but I think that switch is on top of tranny. Not sure if you can reach it from outside. The floor unbolts in that truck to give you access to the top of transmission if needed. Ive got a pretty good stock of Mack parts if you are looking for anything. I bought out most of Tallman transports stock when they closed. Quote Link to comment https://www.bigmacktrucks.com/topic/60471-1998-mack-rb688s-tri-axle-dump-reverse-switch-location-on-tranny/#findComment-439877 Share on other sites More sharing options...
CDNFlatTrackFreak Posted January 9, 2020 Author Share Posted January 9, 2020 Yes I'm from Dunnville. I'm assuming that was a circle P truck. I think I've seen you around the falls with that truck. Can't remember but I think that switch is on top of tranny. Not sure if you can reach it from outside. The floor unbolts in that truck to give you access to the top of transmission if needed. Ive got a pretty good stock of Mack parts if you are looking for anything. I bought out most of Tallman transports stock when they closed.I pmd u my info. Yes it was, and theres 3 running around one is still circle P one is On Point Landscaping (me) and the other is unmarked owned by Rojeen Trucking. Holler at me on 19 next time ur around, I am a younger guy but I do try to keep up the tradition of using the CB, helps pass the days! My best friends Dad is Doug Tallman Sr. I was at those auctions helping out, I was still in high school. Hanging out there is what got me into Trucking. Small world.Sent from my SM-G960W using Tapatalk Quote Link to comment https://www.bigmacktrucks.com/topic/60471-1998-mack-rb688s-tri-axle-dump-reverse-switch-location-on-tranny/#findComment-439878 Share on other sites More sharing options...
DBGraves Posted January 9, 2020 Share Posted January 9, 2020 My reverse switch is on top of the transmission you can pull the shifter boot and look towards the Back you’ll see it. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/60471-1998-mack-rb688s-tri-axle-dump-reverse-switch-location-on-tranny/#findComment-439903 Share on other sites More sharing options...
JoeH Posted January 9, 2020 Share Posted January 9, 2020 (edited) Switch could just be loose. May just need to thread it back in. Could also be a broken wire or terminal in the switch. Edited January 9, 2020 by JoeH 1 Quote Link to comment https://www.bigmacktrucks.com/topic/60471-1998-mack-rb688s-tri-axle-dump-reverse-switch-location-on-tranny/#findComment-439921 Share on other sites More sharing options...
CDNFlatTrackFreak Posted January 10, 2020 Author Share Posted January 10, 2020 My reverse switch is on top of the transmission you can pull the shifter boot and look towards the Back you’ll see it. Similar truck?Sent from my SM-G930W8 using Tapatalk Quote Link to comment https://www.bigmacktrucks.com/topic/60471-1998-mack-rb688s-tri-axle-dump-reverse-switch-location-on-tranny/#findComment-439957 Share on other sites More sharing options...
CDNFlatTrackFreak Posted January 10, 2020 Author Share Posted January 10, 2020 Switch could just be loose. May just need to thread it back in. Could also be a broken wire or terminal in the switch.Ya I will check it out before buying a new one. Seems like the factory wiring is getting to the age where it's getting frail. I use heat shrink like franks hot sauce. Put that shit on everything! Is it switch also accessible from shifter boot? Sent from my SM-G930W8 using Tapatalk Quote Link to comment https://www.bigmacktrucks.com/topic/60471-1998-mack-rb688s-tri-axle-dump-reverse-switch-location-on-tranny/#findComment-439958 Share on other sites More sharing options...
JoeH Posted January 10, 2020 Share Posted January 10, 2020 Honestly I'd put the dump body up and kneel on the floor between the frame and driveshaft and do it from the back of the trans. But I'm also 6 ft and a buck fifty soaking wet. I fit where others don't. Obviously block the dump body so it can't drift down on you. Quote Link to comment https://www.bigmacktrucks.com/topic/60471-1998-mack-rb688s-tri-axle-dump-reverse-switch-location-on-tranny/#findComment-439969 Share on other sites More sharing options...
JoeH Posted January 10, 2020 Share Posted January 10, 2020 7 hours ago, CDNFlatTrackFreak said: Similar truck? Sent from my SM-G930W8 using Tapatalk '95 rd688s with an 8LL 1 Quote Link to comment https://www.bigmacktrucks.com/topic/60471-1998-mack-rb688s-tri-axle-dump-reverse-switch-location-on-tranny/#findComment-439970 Share on other sites More sharing options...
DBGraves Posted January 11, 2020 Share Posted January 11, 2020 My reverse switch is on top of the transmission you can pull the shifter boot and look towards the Back you’ll see it. I have 95 RD688s e7 350 8LL 44k rears Quote Link to comment https://www.bigmacktrucks.com/topic/60471-1998-mack-rb688s-tri-axle-dump-reverse-switch-location-on-tranny/#findComment-440087 Share on other sites More sharing options...
CDNFlatTrackFreak Posted January 22, 2020 Author Share Posted January 22, 2020 Helo my fellow Mack Daddys Instead of starting a new thread figured I'd ask here since truck info is already available. 1. Does anybody know the correct friggin part number for muffler on my truck? All the mufflers for the RB that I come across have the inlet coming into the base of muffler, however my truck and most the R Dumps have the exact same setup with the inlet coming into the side and the outlet is a touch off centered towards cab I believe...also2. the mid pipe which is now flex broke off. Do you reccomend re doing it with flex or buying the proper pipe. I'm exhausted by this3. Where do you folks suggest adding air system antifreeze for preventative maintenance? I have an upper and lower tank on each side, I put a Litre in each top tank. I drained the remaining fluid out 3 day after which was 2 weeks ago, was told to not drain it out?? Had a freeze up on Monday. Suggestions on one or all topics greatly appreciated! Sent from my SM-G930W8 using Tapatalk Quote Link to comment https://www.bigmacktrucks.com/topic/60471-1998-mack-rb688s-tri-axle-dump-reverse-switch-location-on-tranny/#findComment-441081 Share on other sites More sharing options...
alex g Posted January 22, 2020 Share Posted January 22, 2020 Truck repair place in Fonthill of canboro Rd does good exhaust work. Can't think of name at the moment. I think it's J and L though. They'll fix you up right. They did my R model exhaust. Should be a small tank for air put about half a coffee cup of brake line antifreeze in it and leave it. If you can't figure out what tank put it in both. A litre is too much 1 Quote Link to comment https://www.bigmacktrucks.com/topic/60471-1998-mack-rb688s-tri-axle-dump-reverse-switch-location-on-tranny/#findComment-441084 Share on other sites More sharing options...
CDNFlatTrackFreak Posted February 6, 2020 Author Share Posted February 6, 2020 Just wanted to thank you guys for the input on the reverse switch! I took it out by hand and cleaned it. After I cleaned it I thought why the hell could I take it out by hand? It was hand tight and in mint condition. Turns out it just needed tightened. It's quite nice backing up at night with my LED reverse lights instead of putting my 4 ways on. So ya thanks again!Sent from my SM-G930W8 using Tapatalk 1 Quote Link to comment https://www.bigmacktrucks.com/topic/60471-1998-mack-rb688s-tri-axle-dump-reverse-switch-location-on-tranny/#findComment-442062 Share on other sites More sharing options...
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