Question about climbing the Cajon Pass for the SoCal members

I live in Riverside, and have a 939A1 tractor (250 cummins/Auto). I have taken my 5 ton, the "Jolly Green" as it has been named, on a few trips now but will be taking it up to Mammoth over summer which will require a trip up the Cajon Pass. Now I fully expect to be putting along but can anyone give me an approximate speed that they were able to climb the Pass at in a similar 5 ton? It will be towing about 6-7k lbs. I just want to be prepared and be able to make it safely to the sloooow lane at the appropriate time. Thanks. The usual load setup is below.

Don't have your answer but I believe the I15 corridor climbs up to the high desert through Tejon Pass.





Rick

We do it all the time stay in the right lane and you will be fine. I watch the temperature gauges. Flashers below 45 mph and you will probably get down to about 35 mph. Remember to manually downshift the Allison as it helps keep the speed up and temperature down.

rchalmers3 said:

Don't have your answer but I believe the I15 corridor climbs up to the high desert through Tejon Pass.





Rick

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Tejon pass is on the 5 freeway

quickfarms said:

We do it all the time stay in the right lane and you will be fine. I watch the temperature gauges. Flashers below 45 mph and you will probably get down to about 35 mph. Remember to manually downshift the Allison as it helps keep the speed up and temperature down.

Click to expand...

Thanks! That is what I was looking for. Assuming you have the same setup, about what rpm do you manually downshift?

You can take 5 trucks off the assembly line and all 5 will drive differently! Keep the temp down and the rpms in the correct range and you will be fine.

I thought about that drive a few days ago, but I was thinking of going DOWN....
We lived up in Hesperia and drove the pass often, in a jeep... down it in a 5 ton... wow.

My deuce did 26mph up the cajon pass towing the m105 trailer. My m818 with the cummins 250 will do about 35mph up the pass. Just stay In the slow truck lane with flashers on.

You are driving a truck with an Allison.

I downshift as soon as I see the grade, the transmission will only shift when the speed falls enough so that it can with out over revving the engine, this is provided that the transmission is correctly set up.

Driving an Allison is not like driving a car with an automatic.

The cajon pass is nothing compared to some of the other passes. The grape vine is much longer and has more elevation change.

You should be able to come down the pass without using the brakes much.

This all should have been covered in your CDL training.

Once again, thanks for all the info guys!