Rob Posted January 3, 2007 Share Posted January 3, 2007 Hi there, tonight I've looked, scraped, washed, bashed head etc. looking to identify the transmission in my truck. I do know it is a 13 speed Eaton/Fuller, but I cannot find a tag anyplace. There is a flat spot in the case (right side of case) with a couple of holes that look as if there was a metal tag retained with drive screws, but it is empty, and there are no remnants of any fasteners remaining.The rear carriers have 4.17 stamped into them for a ratio, however when the truck was driven up to my shop, the driver stated that it had a lot more to go (road speed) than 4.17 gears would deliver. This tells me the transmission is either an overdrive version (RTO12513?), or the rears have been changed out. I have not driven the truck myself off of my property so I can't give first hand knowlege. I do know that at 60 mph he was right on my rear bumper and later investigation revealed the truck is "turned down" to run only 1800 rpm against the governor via my non contact tachometer, (it is accurate). Without physically pulling the transmission and counting the output shaft revs in comparison to the input, is there any way to discern which transmission is installed? I could break the driveline apart and use my tach to compare the above mentioned revolutions, but that is quite a bit of work. 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/1978-roadranger-13-speed/ Share on other sites More sharing options...
Lmackattack Posted January 3, 2007 Share Posted January 3, 2007 Cant say where to look for the trans numbers but it sounds like you have a overdrive 13 speed. if your truck had a top gear direct transmission with 4.17 rears your top speed at a governed 1800RPM would put you at about 50-52 MPH. even if they were 3.87 rears that would make it around 60-62 @1800.You would need high 2.xx or low 3xx rear ratios to hit 70 MPH. most trucks I have seen dont often come with that low of a ratio...that i know of...Sounds like that dog can run!!! Quote Link to comment https://www.bigmacktrucks.com/topic/1978-roadranger-13-speed/#findComment-9461 Share on other sites More sharing options...
werkhorse Posted January 3, 2007 Share Posted January 3, 2007 RTO12513 is a "double overdrive" is 5th gear position back or forward in the shift pattern?????"double over drives" actually have 3 o/d gear ratio's with top around .70 or something close to that Quote Link to comment https://www.bigmacktrucks.com/topic/1978-roadranger-13-speed/#findComment-9466 Share on other sites More sharing options...
Rob Posted January 3, 2007 Author Share Posted January 3, 2007 RTO12513 is a "double overdrive" is 5th gear position back or forward in the shift pattern?????"double over drives" actually have 3 o/d gear ratio's with top around .70 or something close to thatI will try to find the high gear position this week. I've never been around anything other than a Mack two stick, and an RT-910 that I converted to an RTO when rebuilding.I haven't driven the truck yet as it has an oil leak from the cam/rocker box due to a 5/16" piece of gasket material being "blown out" and it really leaks quite well. I want to fix that and parts should arrive today or tomorrow.Thanks for the help!!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/1978-roadranger-13-speed/#findComment-9470 Share on other sites More sharing options...
b61mack Posted January 4, 2007 Share Posted January 4, 2007 I will try to find the high gear position this week. I've never been around anything other than a Mack two stick, and an RT-910 that I converted to an RTO when rebuilding.I haven't driven the truck yet as it has an oil leak from the cam/rocker box due to a 5/16" piece of gasket material being "blown out" and it really leaks quite well. I want to fix that and parts should arrive today or tomorrow.Thanks for the help!!RobIf it is a double over from the factory it would be RTOO, and high gear would be up to the dash , if someone switched the gears around it would be forward, but a factory overdrive it would shift like any other trans. Quote Link to comment https://www.bigmacktrucks.com/topic/1978-roadranger-13-speed/#findComment-9479 Share on other sites More sharing options...
werkhorse Posted January 5, 2007 Share Posted January 5, 2007 LOL yeah sorry it was supposed to read RTOO Quote Link to comment https://www.bigmacktrucks.com/topic/1978-roadranger-13-speed/#findComment-9520 Share on other sites More sharing options...
twostickmutt Posted January 5, 2007 Share Posted January 5, 2007 i have my tag and can still read it. is there anywhere i can match the numbers as to what year it is and the ratio. it's an old one. it's TRO-9513. fuller /eaton-yale and towne. inc.RTO-9513 is what my fingers meant to say. Quote and remember "PREFORMANCE COUNTS" Link to comment https://www.bigmacktrucks.com/topic/1978-roadranger-13-speed/#findComment-9530 Share on other sites More sharing options...
truxnut Posted January 6, 2007 Share Posted January 6, 2007 The 913-9513 OD boxs had a .87 OD ratio. No way of really telling the year, somewhere between 64-65 and somewhere in the later 70's. Quote John Evans, Trucks & Dogs are expensive!! Link to comment https://www.bigmacktrucks.com/topic/1978-roadranger-13-speed/#findComment-9573 Share on other sites More sharing options...
mechmagcn Posted January 11, 2007 Share Posted January 11, 2007 To tell the difference between a 95 series and a 125 series look at the yoke on the rear of the trannie, If the yoke is close to the seal, it is a 95, if the yoke is about 1" from the seal it is a 125 or later tranny. Both the 125 and 95 series used a reverse shift pattern for the OO, it was only later trans that compensated for this in the shift top. The RTOO9513 trans has a .67 high gear, not real sure of the 125.Jeff Quote 1971 Mack R600 Toterhome "Superdawg" living the life of leisure pulling 1999 NuWa Snowbird 34+2 SE102 "Dawghouse" Link to comment https://www.bigmacktrucks.com/topic/1978-roadranger-13-speed/#findComment-9660 Share on other sites More sharing options...
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