Brandt

I'm running 22.5" spokes. Rims and hubs will get expensive. I have 22.5 tires on my Western Star and trailer. I would rather stay with one tire size.

Thanx. I'll be home in a week, I'll check all of the above.

I have 4.42's w 11R 22.5 tires. I run 1875rpm at 65mph. I have a .78 OD I'd like to re-gear to run 1500 at 65mph

A DOT inspector probably thinks that you need them

Randomly my high beams shut off and leave me in the dark. The time that they work and the time that they are off varries from 30 seconds to 4 minutes. They even shut off on smooth roads and while sitting still. Is there a relay that could be overheating and tripping open?? If so, where would this relay be located? Anything else I should look for??

When I turn my high beams on they work Ok for a while then they shut off - Leaving me in the Dark!! I have tried to time them and it varies from 30 seconds on 5 seconds off to 4 minutes on and 10seconds off. They also shut off and on while traveling on smooth roads and while sitting still. My initial guess was a relay that was getting hot and shutting itself off. Is there a high beam relay?? If so, where is it?? Any other ideas on where to start looking?? Now that the days are getting longer it isn't that big of deal. But, I do want to use the brights to avoid the deer, if I have to drive at night. I'm gonna move this to the Electrical and Lighting section

I'm interested in getting Lockers for my RD. Can I get the parts from a driveline shop or do I have to get them thru Mack. I have 23K Mack diffs. Does anybody know an approx. cost for parts?? Sorry, the "bold" is locked on and I don't know how to get it off.

OK, I'll disconnect before welding. Still not sure on weather I have an ECM or not. I do have an electronic fuel pedal but don't know if it is just electronic for fuel or the full monty.

This is a stupid question, but when did Mack start using computers on their engines?? Did they go complete computer control or did they phase it in with a fuel computer but not a full blown ECM?? The next question is: If my truck does not have ANY computer on it, can I weld on it w/o disconnecting the batteries?? I have a '91 EM7 300

You can on an Eaton, I would assume you could on a Mack. Generally a shop will have bought or made a jig for keeping everything lined up going back in.

+1 on what 84 Superdaog said. With all the "baggage" on this truck I would look for a pre-03 DD. From what I have heard an EGR Detroit is hit or miss as a good engine. Some pull good and get 7.5 mpg, others can't outrun a '66 VW bus and get 4.5 mpg. If I were gambling with $30K I would get an '02 or older. I will take my '99 Western Star with a 12.7 DD to the grave with me (and there will still be life left in the truck!!)

With 4.42's mine runs: 55mph = 1600 60mph = 1740 65mph = 1875 Mine is a TRTXL 1070B 12 spd w.78 OD and 11R-22.5 tires

Usually a syncho - especially if it does it when the trans is cold.

I think the OP used the word underpowered and was referring to HP rating. I didn't read the whole thread but it is my belief the Mack rates the HP where the rubber meets the road. Other HP is rated at the crankshaft. Detroit, Cat and Cummins don't know what type of driveline you are putting behind their engine, so they can't rate it at the rear wheel. Generally you loose 60-75 HP going thru the trans and diffs, so a 427 Mack is actually around 500 at the crankshaft. A 427 Mack will show you 427 HP on a dyno. A 425 Cat or 430 Detroit will show you approx 360-375 on a dyno. If you are using an RTLO trans my 500 Detroit shows 460 on the dyno. The "L" in the trans model means it is a LOW inertia trans and doesn't rob as much HP.

I have a 1070B 12 spd. The info the dealer told me was it has an .78 OD FYI: The taller the OD the less fuel efficient you are. Ideally a direct with 2.90's or 3.08 gears ... would be best.

Turns out Mack wired this truck - BASIC. The T/S and brake share the same wire. I can't split them for the pup, so the pup has to be wired the same way. Not that I need a separate light for the T/S, and a separate light for the brake, but it would be nice to have that option. The drop deck that I pull w/ the Western Star uses the outside (of 3) lights for the T/S and the inside 2 for the brake. If I ever pull the drop deck with the Mack all 3 will be T/S and all 3 will be brake. I think the ABS just needs a constant 12V to the pup/trailer. I remember when I had a spread axle I could drop the air in the rear axle and strap it up (if I was light). When I did this the ABS light would come on because one axle was spinning and the other axle was not. I didn't do this too often as it goofed with the ABS.

Thanx gearhead. The axles that I am using to build the pup, have ABS, my Mack doesn't. I'll hook them up, if they become a problem, I'll disconnect them.

I've got the hole burnt in the pintle plate and am working on the wiring. Everything is color coded but I don't know what the colors are for. So far I have some figured out but there are some that I have questions about. Can somebody tell me if these are correct? Red = brake lights White = ground Blue = ABS (my pup is equiped but the Mack is not - does this matter?) Brown = tail or clearance (which one?) Black = marker or clearance or tail ??? Green = Right T/S Yellow = Left T/S I'm not sure on the tail, marker and clearance lights. Do I have the T/S correct??

What about the gears?? Am I OK there?? I was thinking about something in the 3.90 range. I don't know if changing the gears is cheaper or getting a set of cutoff's from a camel back. If I can fix the 12 speed, I will keep it. I hope it is just the air filter or regulator. - I like easy!!

Sounds a bit out of my price range

Air Regulator? Where is it - what does it look like? Air Filter - didn't know it had one. This could be the problem!! Thank you for being gentle with my ignorance about Mack's. Just got off the phone w/ NW Truck Center (Harold was out for the day). They recomended an injector upgrade and said the turbo should be OK. Both Pyro and Boost gauge are on the short list. I already put holes in the dash for them.

I have had this truck for 8 years and have put very little into it. Next summer I may be working it daily and need to make it more reliable. '91 RD690S Maxidyne EM7 300 4 VH 12 speed TRTXL 1070B Mack diffs w/ 4.42 gears (CRDPC92, CRD93) Camel Back Double frame The syncro in the trans is GONE. Going up or down - everytime I move the button on the stick it grinds. It is particularly bad when I move the button to go down and the stick to go up a gear. My options are to replace it with a Mack 18 spd, replace it with an Eaton 18 spd (and have a new drive shaft made) or rebuild this trans. I like the Eaton idea as it will get me better fuel mileage, but the Mack 18 spd is built a bit stronger. Your thoughts?? I need more HP. I got spoiled with a 60 series 500 HP and now feel the Mack is under powered. I will be adding a Pittsburg Power muffler and maybe a turbo this winter. Any other hod rod ideas?? I want to pull a pup with this and will be grossing 92,000 lb. While a 300 may get me by in Ohio, it will be a real struggle at 5000' in the "hills" of WY and MT. My jake brake is weak. The truck didn't come w/ this, I added it shortly after I bought the truck. I got the parts from a salvage yard in IL. I was told that there is a kit to increadse the oil pressure and get a stronger jake brake. I have no other info. If anybody knows how to get more braking power out of my jake, I am very interested!! I also need several small parts. I recently blew a steer tire and it wiped out my passenger side headlight assy. The hood is mildly cracked but I can work with it. Other than the dealer is there a place that has Mack parts like this?? Aftermarket is OK as long as they are not chineese parts. Sorry for the lengthy post, but I always had the $$ to pay a mechanic when I was running over the road. Now that I am semi-local I want to do more myself as well as I don't have the money to pay somebody else.

No "R" model should die in vain. Thru this death others may live!! I'm looking at the parts I can use to keep mine alive. Does the owner want to part out the truck??

That worked!! Thanx I'm kinda proud of the Western Star too!