macattack

sorry slip yoke is there. right after the center bearing. just poor pic. tuff to get the whole shaft pictured.

just took a good look at the driveshaft on my mr688s truck and noticed this. i think i need to spin the drive shaft so the front half is in phase with the rear. notice the yoke at the trans is opposite the yoke at the power divider. pic 1 shows from trans to center bearing and pic 2 from center bearing to rear axle.

thinking of installing front shocks on my mr688s truck. anybody have part numbers for the brackets and or pics on where they would mount. do you think i may be better off with air bags? thanks

thanks guys. gonna check out the monroe and gabriel shock sites see about those kits. yah some mechanics today, when i first took it in for a safety they replaced brakes, air valves, u joints etc.... and 4000.00 later it was done. brought the truck home and one day later i noticed a broken rear leaf spring??? sometimes best to check yourself i guess.

does any other mr owners have part numbers for a shock add on kit. my mr688s does not have front shocks and i am thinking of adding, but need part numbers or pics. thanks

thanks again guys. gonna try rotating 180 and see what happens. anybody have part numbers for a shock add on kit?

thanks guys. spoke to the tire shop where i purchased the hercules and he said he will try and see if he can return them. anyways 84 superdog you stated it might be a loosing battle do you think i should try a front air suspension kit. these mr688s dont have front shocks either. i never thought of rotating the tire on the rim.. sounds like it might be an idea. do you think i could just turn the rim and tire maybe 1/4 or 1/2 turn. yhis way i dont have to dismount the tire from the rim?

going to check with the tire shop tomorrow and see about returning the fronts and exchange for a higher quality tire. my rears are also new. couldnt comment on if truck did this with the original tires, i never got a chance to drive it with the original tires. i do know that without any balance beads the truck hopped alot worse. leversole let us know how you make out with trueing the tires.

thanks guys. yah pita to have to change out my fronts. hell i just replaced both steers and all my drive tires. all new no retreads. my fronts might have 500 miles on them. do you guys think i should go for a 445 or a 465 rather than the 425 fronts. maybe this mr688s needs a bigger tire? i dont know.

well been struggling with this hop issue i have had for a while. you know the usual hop around 40mph . before 40 and after 40 just fine but around 40 mph there is a hop. had a 3 axle alignment done. everything is perfect, no adj needed at all. in fact the mechanic at the alignment shop told me it looks like new under there. anyway he took it for a drive and figures my front tires. i told him they have balance beads installed. anyways he thought maybe to add more beads. so he added a couple more ounces and my hop got worse. so now he took out the beads and added only 16 ounces. hop is back to normal. he figures that the cheap hercules tires is my problem. i have 42565r225 hercules on the front. he says that they a cheap overseas tire and they are a bitch to balance. what do you think? maybe i should go to a 445 or a 465? he says drive it and put some wear on them a see what happens. anyways my truck did pass the safety.

can a trans cooler for a 740rs allison cooler be cleaned or is it best just to replace. i began to notice that after a drive i get some fluid spitting out of the dipstick when i shut the truck off. i dont think its overfull. site glass shows full when cold and about half warm. any tips on replacing the cooler/ the truck has a e7 300 engine. thanks

i do have a second truck, but different rims.

thanks for the info. the rear brakes have auto slack adjusters and they all seem to be be working fine. is there such an adjustment on the fronts?

i never knew that. anyways i quickly checked my toe in. just using a tape. 92 1/2 on the rear of the front tire and 92 on the front of the front tire. way too much toe in, should only be about 1/8. dont know if this will cause a wobble or not , but still too much. anyways do i just jack up the front and loosen the 2 tie rods and turn the link rod? thanks

thanks guys. lots of interesting posts on the tires. well i booked her in for a 3 axle alignment and going get those tires changed out. sounds like the michelins are the way to go. anyways had her on the road today, just to double check my last findings. with the arms up the truck develops a wobble that starts at 35 and ends at 40mph. but with the arms down the wobble turns into a hop? this occurs in gear and coasting. 84superdog stated he gets the tires trued. does that mean balanced??

do you think it may be the cheaper tires at fault?? the hercules run around 750.00 each and a goodyear around 850.00.

hey gang. been tackling this wobble thing for a while now. changed and checked alot of things and last weekend stumbled across this. the truck is a mack mr688s front load garbage truck. if i drive with the arms fully raised i have a wobble from 40-45 mph after 45 she is fine. this is either empty or loaded. if i drive with the arms down there is no wobble. the truck drives great. the arms do weigh a ton. what it feels like is the truck is definately lighter on the front end with the arms up. now the manual says operate highway with arms up. do you guys think i should get front air installed or will a higher quality front tire do it. i have a new set of hercules 425 65r 22.5 on the front rite now. the truck feels light on the front end. thanks

does this have air controlled throttle? mine has a auto trans with air throttle control. my torque converter locked up on me and i couldnt move at all. bad modulator valve. replaced and she is fine.

thanks for all the info gang. i actually never got to drive it with the old tires, but i know they were alot narrower tires on the front. i am gonna swap out those hercules and have the toe in checked. see what gives. thanks again gang.

thanks guys. would an out of round tire smooth out after 45 mph? mine shakes the truck between 40-45 mph after 45 its fine. i would think an out of round tire would always be shaking?? or is my thinking wrong.

just wanting to know if any other mr688s owners know if they have one or two spring wedges. one per front side? mine only has one and i am thinking the original owner had some spring work done on the pass side and didnt replace the wedge on that side. should the wedge be installed thick to back axle or to front bumper? my question is if my caster was out of adjustment because of one wedge would this cause my truck to wobble from 40-45 and after 45 she rides nice. feels like a flat spot on my front tire. but there brand new and checked out fine. i have beads installed and that helped but not a 100%. dont know if it s the cheap made in china HERCULES 425 65r 22.5 fronts or the one wedge misssing. also if i needed a caster adj would my steering wheel shake. because its smooth. happens when coasting also. thanks

i have much the same problem on my mr688s. around 40-45 mph. starting to think i either need an alignment or maybe replace my front steers with a higher quality tire. i have hercules 425 65r 22.5 fronts. maybe i should try a goodyear or michelin? did alot of work to try and solve this. replaced springs, pads, bushings, torque and transverse rods, tie rods hubs etc....... all new tires fronts and rears. all with balance beads. dont know if its common with the mr models as well. as stated before by other poster . no shake in the steering wheel at all. i can remove my hands and she will drive straight. just a wobble feel at 40-45 then goes away. does the same coasting. did notice that i have only one spring wedge on the driver side front and none on the pass side front. maybe an alignment would be my best bet, what do you guys think??

thanks i did not realize this.

how did you tightened up the king pins? also could you explain how you would tighten up the wheel bearing. thanks. good to know you have it fixed.

those step by step pics would be GREAT!!!