Deere Mack Posted February 7, 2014 Share Posted February 7, 2014 Good morning folks! I'm looking at buying a 98 RD688s with a 350 mack and 8LL trans. The truck has a little growl when going from low to high but does go into place. It doesn't jump out of gear and shifts well. What might the problem be and should it be a big concern? Thanks! Quote Link to comment Share on other sites More sharing options...
Deere Mack Posted February 7, 2014 Author Share Posted February 7, 2014 I've read what I could find on here, but the problems I've seen on here are going from Hight to low, not low to high. Same problem? Quote Link to comment Share on other sites More sharing options...
steeler Posted February 7, 2014 Share Posted February 7, 2014 Sounds like syncro going south. It will get worse, to the point it will not stay in High range. Quote Link to comment Share on other sites More sharing options...
2stacksuperdog Posted February 8, 2014 Share Posted February 8, 2014 I guy i know has this problem with his International. He dont take it on the highway anymore. Quote Matt Link to comment Share on other sites More sharing options...
Deere Mack Posted February 8, 2014 Author Share Posted February 8, 2014 I would expect that from an International . The guy says it has been doing it for a few years and it hasn't gotten any worse or better, he drives it everyday. I'm thinking it is the syncro also, any rough ideal on cost to repair? Quote Link to comment Share on other sites More sharing options...
Challenger Posted February 9, 2014 Share Posted February 9, 2014 Its the beginning of a synchro failure, not sure on Eaton prices. Quote Link to comment Share on other sites More sharing options...
bbigrig Posted February 13, 2014 Share Posted February 13, 2014 Pricing will be a lot less then having to do syncros on a Mack Trans.If you have a guy that knows what he is doing, he will pull the Aux box (rear housing) of the transmission that holds the syncro pins and collar while still on the truck.it can be rebuilt and reinstalled fairly easily after dropping the driveshaft etc.In Mack's case you would have to pull the entire trans, then pull the rear gearcase, then replace the syncro clutch pack......blah blah....Saves a ton on labour and the parts are about 2/3rds of what Macks are. Quote Link to comment Share on other sites More sharing options...
Deere Mack Posted February 13, 2014 Author Share Posted February 13, 2014 Pricing will be a lot less then having to do syncros on a Mack Trans.If you have a guy that knows what he is doing, he will pull the Aux box (rear housing) of the transmission that holds the syncro pins and collar while still on the truck.it can be rebuilt and reinstalled fairly easily after dropping the driveshaft etc.In Mack's case you would have to pull the entire trans, then pull the rear gearcase, then replace the syncro clutch pack......blah blah....Saves a ton on labour and the parts are about 2/3rds of what Macks are. I appreciate the info. I know gears grinding is never a good thing, but can it harm anything else in the trans if it doesn't get fixed or can I drive it until it has to be repaired?. I drover the truck again the other day and it only done it once out of several tries. Quote Link to comment Share on other sites More sharing options...
theakerstwo Posted February 13, 2014 Share Posted February 13, 2014 On a eaton trans when it grows as your saying between ranges its asking you to repair or I am going to make you pay. Some times what happens is one of the pins break off and fall down and go thru two gears breaking the case.Right now I will more likely need a syncro kit and sliding clutch plus the aux drive gear on the main box plus grease and gaskets and seal.But some times it don't break any gears so its your call. Quote glenn akers Link to comment Share on other sites More sharing options...
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