310 Isuzu Diesel Vibration FREE!!!

[gcgreenwood]

Finally the vibration in the drive line is fixed. Jackson Truck Service here in Jackson Michigan was able to cure the problem. They had to reposition the engine and tranny plus correct ALL the angles in the driveline. I also had them install the US Gear overdrive unit. Took a lot of trial and error to get it right. Absolutely NO vibration at any speed. The coach now tops out at 73 mph. Runs at 65 at about 2750 rpm.

A big thank you to JTS.

Gary

Leslie, MI

[Mike Leary]

Originally Posted by 44tonner

Absolutely NO vibration at any speed.

If you ever look at the paperwork for o.d. units, you'll see how the alignment is so important with the driveshaft and u-joints. Glad you re-did it.

[ScrapIrony-2]

Congrats on the repairs!!!I can't get going that fast unless I'm going down a 6% grade...m

[silverback]

Hi Gary,
Why did they have to reposition the engine? I'm interested because our Excella 280 has a new Isuzu diesel (with the Isuzu factory turbo) and we have no vibration. Maybe that was already done to ours? I'm also real interested in the US Gears OD/UD. We have a shop in Phoenix that wil install the Gear Vendors or US Gear ODs. The US Gear is a $1K less expensive.

-Ken

[ScrapIrony-2]

We have a GV overdrive, and as far as I can tell, it will give us 1 mpg in savings...doesn't work in the mountains(and shouldn't be engaged in that terrain), but AZ and west Texas/southern NM are great for it...just have to remember to engage it...
m

[gcgreenwood]

The 310 has 3 drive shafts. When JTS checked it, they said ALL the driveline angles were off. They needed to reposition the engine/tranny to get them back where that needed to be. Plus shim the two driveshaft bearings and rotate the rearend a bit.

While doing all this, they found the flexplate cracked around the crankshaft bolt circle and the transmission case starting to crack again. They installed a new flex plate and welded the transmission case. We are pretty sure with repositioning everything it is now fixed for good.

As to the US Gear OD unit, I would call them as I think I got the last one they had for the 475 transmission. They still make the OD unit but don't think they have any more of the adapters for the 475. Yes they are less money. They are also US made.

When I first drove it, it was in High range. Didn't realize it. Seemed to run fine, even starting out from a stop. I tried it out on some long hills, and as it slows down, just down shift it into the normal range and it keeps chugging up the hill. If it's long steep hill maybe shift into second and put the od unit in high, a split shift. I have no idea at this time as to any mileage difference. I do like it that I can run at 65 with no problem. When I drove it back from CA where I bought it, 55-60 was tops at 3200 rpm. Now it will do 70+ if need be.

Gary
Leslie, MI

[ScrapIrony-2]

Gary,
My understanding is that in steep terrain(mountains), Overdrive will burn itself out, as it has to constantly change for the optimal gearing...we only use ours in relatively flat touring...mike

[gcgreenwood]

The US Gear OD is rated for 35,000#s of load. Way more that a fully loaded 310 @ 15,000#s. If you didn't down shift it, I could see the exhaust temp going too high, or tranny temp going up or even over heating the engine. I don't see any way you could hurt the OD unit. It dosen't have any clutches that can slip. They are dog clutches with no clutch plates. I did notice with it in high range the turbo pressure gets over 10# real quick. If it was a long hill I'm sure the exhaust temp would get over 1200 for sure. That would start cooking things.

Gary
Leslie, MI

[ScrapIrony-2]

Originally Posted by 44tonner

The US Gear OD is rated for 35,000#s of load. Way more that a fully loaded 310 @ 15,000#s. If you didn't down shift it, I could see the exhaust temp going too high, or tranny temp going up or even over heating the engine. I don't see any way you could hurt the OD unit. It dosen't have any clutches that can slip. They are dog clutches with no clutch plates. I did notice with it in high range the turbo pressure gets over 10# real quick. If it was a long hill I'm sure the exhaust temp would get over 1200 for sure. That would start cooking things.

Gary
Leslie, MI

OK, just passing on what the tranny shop told me, and what the GVOD book says...mike

[silverback]

Gary/Mike,
With either a US Gear or Gear Vendor OD, I can simply turnoff/disengage the OD for long ascents or downshift with column shifter (like I normally do) with the OD still engaged. Is that correct?

Thanks,
Ken

[John H.]

Originally Posted by ScrapIrony-2

Gary,
My understanding is that in steep terrain(mountains), Overdrive will burn itself out, as it has to constantly change for the optimal gearing...we only use ours in relatively flat touring...mike

Took the 345 through west Virginia and did the Hill thing real hard. the G.V. Never searched ! NOT One time !! Just pulled, Wowww, was I impressed, I to tried it . I switched it of ! lost speed, increased RPM, Turned it back on, took off up the hill, Lower RPM and gaining speed !!

I love it !!!