HK Trucking

All of the Bulldogs up until 2001 stood up on their hind legs - they were proud. Since 2001 (the V*lvo takeover), well, their new foreign master abused them, so now the Bulldog is cowering, wondering when he'll be "put to sleep".

Amen!!!!!

And there's the problem in a nutshell. Evidently the input from you guys here in the U.S. is disregarded by the Volvo bigwigs. Mack is (was) the greatest American truck and it's being emasculated by foreigners who have no f***in' clue.

Original color for Mack diesel engines in B models was a bluish green color, similar to the Detroit Diesel color of that era, but with a bit more bluish tint to it. Like the color of this sentence.

Look here: http://www.bigmacktrucks.com/index.php?showtopic=3805

For 11R22.5's you want 8.25 inch rims. Here in WI that size rim is a dime a dozen, whether Dayton, Unimount, or old type Budd. Those 9 inch rims are good for someone who wants to upgrade to 315/80R22.5's on a steer axle, I'm sure you could sell them easy enough. Yes, I have seen 7" 22.5 Dayton rims, bought a set at a local junkyard once to use on a pusher axle.

A photo of the RB688s that I had: It had an E7 400 with a T2130 Mack 13 speed, would run away from "brand x" trucks with C15 Cats & ISX Cummins motors.

Actually, I think the problem lies with the Swedes at Volvo.

Venezuela. Hugo Chavez is the dictator. Currently Diesel fuel is 4.799 here. WTF.

To answer your other questions, you can use all the combinations or whatever you need to keep the engine RPM's in the proper operating range depending on conditions. When empty you can drive it like a 5 speed if you want.

5x2 without deep reduction = 10. 1st gear with either the high or low split while in deep reduction =2. Total of 12 speeds.

5 speeds on the stick in the standard "H" pattern, reverse is on the air shift knob, enabling the use of all 5 speeds in reverse as desired, also on the air shift knob is a hi/lo splitter which you can use to split each of the 5 gears in half, similar to operating a 2 speed rear. Depending on the vintage of your 12 speed, it may have another shift lever for the deep reduction off road lo range, or if it's a newer one (TRTXL1070B) it will have an air switch on the dashboard for the deep reduction.

A T2060 in lo range 1st gear with 6.34 rears gives an overall reduction of 57.19:1. A T2060 in lo range 1st gear with 7.00 rears gives an overall reduction of 63.14:1. Those rear end ratios will get you in the ballpark for decent startability off road. The problem is that by using those low rear axle ratios, even at 2100 RPM the truck will have a top speed of 60 MPH with the 7.00:1 rears or 66 MPH with the 6.34:1 rears. Since the T2060 was most often used with the EM7 300L which had a max RPM of 1750, unless you mess with the pump to get the RPM's to 2100, you'd have a top speed of 50 MPH with the 7.00 rears, or 55 MPH with the 6.34 rears @1750 RPM. The T2060 just does not have enough of a spread between lo range 1st gear and 5th hi range to have enough reduction for off road use while still being capable of an acceptable top road speed, you can achieve one or the other, but not both.

I don't have my Mack manuals handy right now as we recently moved and they're still packed away, have to find them soon. My original reply was based on real world experience. Also, what I have found over the years is that if you multiply the lowest gear ratio in the transmission by the rear axle ratio, the total must be at least 60:1 in order to have acceptable startability during off road or heavy load conditions. This formula applies to trucks on 10:00-20 or 11R22.5 rubber, for a truck with larger rubber, the total would need to be greater in order to achieve the same result. Therefore, using the ratios posted by GHG and David, the T2060 low gear ratio of 9.02 multiplied by the rear axle ratio of 5.73 would give a total reduction of 51.69:1 which is far short of what's needed. I've also seen some trucks with the T2060 that had 5.55 or 5.05 rears which would result in a total reduction of 50.07:1 and 45.56:1 respectively, even more unacceptable. Bottom line: One of the transmissions mentioned in my original reply is the way to go.

A 13 speed would have a synchronizer on the hi - lo range shift, but that would have no effect on popping out of reverse. I concur with Glenns advice, and also would suggest checking for a broken detent spring or stuck detent ball on the reverse - lo shift rail, or possibly the transmission has been abused and the sliding clutch teeth on reverse are so worn that it jumps out of gear under pressure. Whatever the cause, fix it immediately, as a transmission jumping out of gear under load will send shock waves thru the entire driveline leading to other problems in the future.

....but you have to remember, Volvo is here to help make Mack better.

The T2060 doesn't really have a deep enough reduction in lo range to make it suitable for heavy hauling IMO. With a T2060,in order to have enough overall reduction for good startability off road or with a heavy load you would have to use a lower rear axle ratio, and if you do that, your maximum road speed in hi gear will be reduced If you want to stay with a T200 series transmission, the T2070 or T2080 would be much better. The T2060, 2070, and 2080 are used with Maxidyne engines. Another option yo may want to consider is the TRTXL1070B 12 speed, this is a TR107 series transmission which has an off road Lo Lo, and an overdrive in hi gear to give you the best of both worlds. All the transmissions mentioned are the triple countershaft design and are virtually indestructible. A non Mack option for your application would be the Eaton Fuller 18 speed, or 8LL.

Don't cut on a tank with an oxyacetylene torch! When you hit the cutting lever on the torch you'll be pushing pure oxygen into the tank thru the cut. Combine that with the diesel fuel vapors and you're creating a bomb. Use a cutoff wheel or some other method.

Also, in my earlier post I should have emphasized that when you are welding on a diesel fuel tank, you must remove the fuel cap and all pipe fittings and plugs from the tank. This is to prevent a pressure buildup in the tank from the heat of welding, which could cause an explosion. Only plug off all the fittings in the tank while pressure testing, leave everything open while welding. And, DON"T TRY TO FIX A GASOLINE TANK THIS WAY!!!!!!!!!!

I'll second that.

.... and then pressure test the tank after you're done welding and before installing it on the truck. About 5 psi is plenty, then spray all the welds with a mixture of Mr. Clean and water while the tank is pressurized.. You'll see bubbles immediately if there are any pinholes, if so, clean off the leaky area, then re weld and pressure test again. Repeat if necessary.

The 237 will basically be a bolt in swap with the exception of air intake & exhaust plumbing, and depending on what model of truck the 237 came from you'll probably have to use the water pump & harmonic balancer from the 673. The main problem I see with your plan is the 5 or 6 speed transmission. Assuming you are referring to a TRL 107 5 speed, or TRXL 107 or 1071 6 speed, these transmissions are direct in high gear, whereas the quad box has about a .70 overdrive in 5th hi IIRC. The quad box is direct drive in 4th direct, so whatever your top speed is in 4th direct with the quad box, that's going to be your top speed in high gear with the 5 or 6 speed. Most B61's on 22" rubber ran either 7.00 or 7.49 rear axle ratio. If you go with the 5 or 6 speed, you'll want 4.50 or 4.64 rear gears, that would put you in the low 60's @ 2100 RPM, and give you enough reduction on the lower end. If the truck is just a toy and not going to pull anything heavy, then you could go to 4.17 rear gears. My question is why would you want to swap the quad box for a 5 or 6 speed?

Because 5th Lo Split and 5th Direct are a lower ratio than 4th Hi Split When you're ready to upshift from 4th Hi Split you just shift the main to 5th, leave the compound in Hi Split. BTW, in case you didn't know, Lo Lo is not a part of the on road shift sequence, Lo Lo is just for use in extreme conditions in 1st or 2nd gear only.

Yes, the springs and the toothed parts on the plungers Not spinning, but rotating about 90 degrees or so from shut off to full throttle. (With the engine off @zero RPM, the governor will put the rack to full fuel as soon as the stop control moves to the run position if everything is free in there)