I upgraded my tranny from 16913 to 18913 (higher torque rating) and the mechanic replaced worn out bearings ... but it didn't change how the tranny shifts when I use low and high splits. Especially when fully loaded, I experience jerks when going from 5 high to 6 low, or from 6 low to 6 high. It happens only in these 2 gears and only when the splitter is used. If I shift from 5 low to 6 low and then to 7 low, everything is great. The clutch is new, LIPE 2,000 torque rating. I tried playing with different RPMs at change and jerks become much less pronounced when I accelerate to something like 1400 or 1500 RPM. Can it just be a case of poorly matched tranny and the truck specs?

Originally this 2004 International with a 410 HP Cat C15 Acert had a 10 speed tranny with 295 tires and 3.73 ratio. The previous owner replaced the 10-speed with a 13, and I upgraded the engine to 550 HP and the tranny to 1850 torque rating. The axle ratio and tires are still the same.

I'm thinking of losing the 3.73 rears and putting in 3.58s or even 3.42s and wonder if that might make shifting smoother?

Any comments?

Here's my gear box in black and white

RTLO-18913

GEAR RATIO
8 H 0.73
8 L 0.86
7 H 1
7 L 1.17
6 H 1.38
6 L 1.62
5 H 1.94
5 L 2.28
RANGE SHIFT
4 3.23
3 4.43
2 6.11
1 8.59
Low 12.31

 

When I was driving CRST and had a co driver, we had this International that would act like it was trying to tote the front tires. When driving it, you just had to be smooth on the accelerator pedal and it would be ok. When he got behind the wheel I could not get any sleep back there. IF memory serves me correct, it was worse unladen.

10 speed btw

 

Re you pushing the clutch in on every shift? Try leaving the clutch pedal alone and floating the gears into mesh with the gas pedal. Once you get the hang of it, nothing works slicker than a Fuller transmission, shifted without the clutch.

 

You only experience jerks when shifting certain gears? I see them all the time, mostly in 4 wheelers but sometimes in big rigs.

 

I agree, I have a old 13 speed in my KW I use the clutch for 1st (or whatever gear I decide to take off from a stop in) and reverse thats it! Is this a used trans then that just has new bearings installed? IMO if changing your shifting habbits dont fix it, then it may be something in the transmission like a knarled up set of gears from whoever had it before you bought that trans!

 

It is not a case of poor match. It is probably first signs of wear in the overdrive splitter. When you split in high range, the split shouldn't take place until you relieve pressure on splitter by taking foot of accelerator, it sounds like the transaction is happening prematurely, I have rebuilt many thirteens but still this is only a guess. If that is where the problem lies you do not have to remove the transmission to repair. Just the aux. section, and it shouldn't be to expensive a repair.