firelinefps Posted January 12, 2013 Share Posted January 12, 2013 Last summer I bought a 1990 Mack RB690s S with a Kpac hooklift/roll off system on it. It has the T2060 transmission. I thought all the T2060's had a high/low range, but the dealer I bought this truck from said this one didnt. It has R, 1, 2, 3, 4, 5 but no high/low flapper on the gear shift, it does have the aire lines coming up the shifter rod but no flapper. My main reason for asking is that I have put this and some other equipment up for sale do to the lack of work in my area and I just want to be able to have the right information to pass to perspective buyers. Thanks for any help. Quote Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/ Share on other sites More sharing options...
David Posted January 12, 2013 Share Posted January 12, 2013 Crawl under the truck on the drivers side and read the numbers stamped in the side of the transmission. 2050 is a five speed. 2060 is a six speed. Quote Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-156850 Share on other sites More sharing options...
Vladislav Posted January 12, 2013 Share Posted January 12, 2013 What does the shift sticker on the dash tell? Quote Никогда не бывает слишком много грузовиков! leversole 11.2012 Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-156852 Share on other sites More sharing options...
umodelnut Posted January 12, 2013 Share Posted January 12, 2013 The shift sticker on the heater cover is the pattern. Wouldn't it tell on there if there is high or low? And I would go with David, the number stamped on the drivers side of the tranny, check the numbers. Quote Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-156857 Share on other sites More sharing options...
terry Posted January 12, 2013 Share Posted January 12, 2013 I believe that series of tranny has a lo-lo on the air shifter along with the reverse. Terry Quote Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-156865 Share on other sites More sharing options...
firelinefps Posted January 12, 2013 Author Share Posted January 12, 2013 The sticker on the dash says its T2060, the Build sheet from Mack says a T2060. I toook a couple more pictures I'll post. I sure can't figure out how to switch from high/low, This shifter doesn't move or flip or anything, what am I missing? Quote Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-156870 Share on other sites More sharing options...
2stacksuperdog Posted January 12, 2013 Share Posted January 12, 2013 I think your missing you button which goes to low Quote Matt Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-156872 Share on other sites More sharing options...
terry Posted January 12, 2013 Share Posted January 12, 2013 I was wrong on the reverse on the air shifter, but you are missing the flipper for the lo-lo gear, Quote Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-156873 Share on other sites More sharing options...
firelinefps Posted January 12, 2013 Author Share Posted January 12, 2013 What would be the reason for the previous owner to remove the flipper? I don't get it. Quote Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-156877 Share on other sites More sharing options...
2stacksuperdog Posted January 12, 2013 Share Posted January 12, 2013 (edited) either it probably don't work or most likely it got hit and broke it off they are only plastic Edited January 12, 2013 by 2stacksuperdog Quote Matt Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-156880 Share on other sites More sharing options...
firelinefps Posted January 12, 2013 Author Share Posted January 12, 2013 Does anyone have a pic of what it should look like? Would it have to be plugged somehow? Quote Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-156883 Share on other sites More sharing options...
leversole Posted January 12, 2013 Share Posted January 12, 2013 The button is plastic, but the metal plate the button attaches to is the valve plate...it is either broken off, or the previous owner took the plate out...either way, the air is probably cut off to the stick... 1 Quote Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-156888 Share on other sites More sharing options...
firelinefps Posted January 12, 2013 Author Share Posted January 12, 2013 Thanks, I guess I'll have to get it to a dealer and see what they say or what can be done. Quote Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-156892 Share on other sites More sharing options...
Lmackattack Posted January 12, 2013 Share Posted January 12, 2013 A 2050 (5speed) does not need any air to shift the trans. A 2060(6speed) uses air to put the trans in lo-lo a 6 speed shifts as follows. 1st Lo-lo, flip to hi 1st,2nd,3rd,4th,5th only need the air flipper to get in and out of lo-lo Quote Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-156899 Share on other sites More sharing options...
firelinefps Posted January 12, 2013 Author Share Posted January 12, 2013 Thanks guys for your help, after seeing the pictures so I knew what to look for I jumped in it and could see the valve plate and the hole where the plastic flipper must screw into. I put a screw driver into the hole and the valve plate switches back and forth just fine so I'm hoping it was just broke off and they never fixed it. When it warms up a bit, i'll fire things up and take her for a spin. It will be like Christmas if it all works! Quote Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-156917 Share on other sites More sharing options...
Challenger Posted January 13, 2013 Share Posted January 13, 2013 Im going to guess and say the original owner may have broke the lever off to keep drivers from driving it like a 10 speed and tearing up the back case. People get in a truck with a lever on the shifting knob and think they have a Hi and lo side. This trans does not have a synchronizer. Every T2060 I see has a failure in the aux case because of improper shifting. If lo reverse and lo 1st arent needed I would leave it in high and drive it like a 5 speed. Ive taken the air shift lever and airlines off by owner request just to prevent future failures. Even if the owner is the only driver, somewhere some mechanic will get in and attempt to shift it like a 10 speed and start the failure. Sounds like the previous owner paid for trans repairs due to improper shifting. Its a simple costly mistake that WILL happen. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-156938 Share on other sites More sharing options...
Popular Post 2stacksuperdog Posted January 13, 2013 Popular Post Share Posted January 13, 2013 Im going to guess and say the original owner may have broke the lever off to keep drivers from driving it like a 10 speed and tearing up the back case. People get in a truck with a lever on the shifting knob and think they have a Hi and lo side. This trans does not have a synchronizer. Every T2060 I see has a failure in the aux case because of improper shifting. If lo reverse and lo 1st arent needed I would leave it in high and drive it like a 5 speed. Ive taken the air shift lever and airlines off by owner request just to prevent future failures. Even if the owner is the only driver, somewhere some mechanic will get in and attempt to shift it like a 10 speed and start the failure. Sounds like the previous owner paid for trans repairs due to improper shifting. Its a simple costly mistake that WILL happen. My dad was a mechanic for Gulf and they bought a bunch of 88 R models with T2060s in them and he could not get it through to the drivers you only split first gear but they still tried splitting every gear anyway. 3 Quote Matt Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-156940 Share on other sites More sharing options...
firelinefps Posted January 13, 2013 Author Share Posted January 13, 2013 That makes sense....thanks for that information, maybe I will just leave it off....I would hate for this truck to get tore up like that, it's too nice of a truck. I really appreciate all your information. Quote Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-156992 Share on other sites More sharing options...
57 bcr Posted January 13, 2013 Share Posted January 13, 2013 I believe that is the same shiftknob assembly used in the old Spicer air 4x4's.I rebuilt the knob for my KW,only to find out the trans was bad.OOPS! The rebuild kit through Weller Truck Parts ran me like $105.00 at the time (3 years ago).It came with the plastic knob (thats missing on yours)and the whole "guts" of the valve. Quote IF YOU BOUGHT IT, A TRUCK BROUGHT IT..AND WHEN YOU'RE DONE WITH IT, A TRUCK WILL HAUL IT AWAY!!! Big John Trimble,WRVA Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-156994 Share on other sites More sharing options...
1951 Mack LJ Posted January 13, 2013 Share Posted January 13, 2013 Why not just put an air valve on the dash somewhere for the low range? Quote Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-156995 Share on other sites More sharing options...
Lmackattack Posted January 13, 2013 Share Posted January 13, 2013 Alot of slip seat drivers had a hard time with the 2060,2070 transmissions. Quote Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-156997 Share on other sites More sharing options...
David Posted January 13, 2013 Share Posted January 13, 2013 Alot of slip seat drivers had a hard time with the 2060,2070 transmissions.That's why their called steering wheel holders. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-157067 Share on other sites More sharing options...
Green Dash Posted January 13, 2013 Share Posted January 13, 2013 That's why their called steering wheel holders.And why there's a a plate/sticker somewhere in the truck showing how the shift the transmission. So many transmissions use the same lever and air switch, look at the older Roadrangers. I don't know why anyone would assume which transmission they were operating when often times all you have to do is look around or maybe put the the effort into pulling down the sun visor. 1 Quote Jim Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-157072 Share on other sites More sharing options...
HK Trucking Posted January 13, 2013 Share Posted January 13, 2013 Im going to guess and say the original owner may have broke the lever off to keep drivers from driving it like a 10 speed and tearing up the back case. People get in a truck with a lever on the shifting knob and think they have a Hi and lo side. This trans does not have a synchronizer. Every T2060 I see has a failure in the aux case because of improper shifting. If lo reverse and lo 1st arent needed I would leave it in high and drive it like a 5 speed. Ive taken the air shift lever and airlines off by owner request just to prevent future failures. Even if the owner is the only driver, somewhere some mechanic will get in and attempt to shift it like a 10 speed and start the failure. Sounds like the previous owner paid for trans repairs due to improper shifting. Its a simple costly mistake that WILL happen. That will be all well & good until the truck gets into some soft ground or has to start off loaded on a steep hill & the driver smokes the clutch trying to get it moving without lo lo. 1 Quote "If You Can't Shift It Smoothly, You Shouldn't Be Driving It" Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-157074 Share on other sites More sharing options...
slpwlker Posted January 13, 2013 Share Posted January 13, 2013 Damn how hard is it to read the shift pattern where ever it might be if it isn't removed. Every truck I have ever driven thats the first thing I looked for. Hauled a few Mixers that had Mack 7 speeds. think it was lo 1-2 hi 1-5. Different but as it was said steering wheel holders 1 Quote Link to comment https://www.bigmacktrucks.com/topic/29348-t2060-in-a-1990-mack-rb690s/#findComment-157075 Share on other sites More sharing options...
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