We are going to be going to the Thousand Trails Yosemite Lakes campground in the next month or so. We will be coming from the Central Valley up Hwy 120.Can anyone tell me what to expect(both up and down) on Priests grade? I have driven this in a car but never towing a 26 foot trailer with my Ford Ecobeast. Any advice?

Make sure you take the newer side, not the "old" Priest Grade. You won't have any problem at all, I did it not long ago with my 32' MH pulling a car. As you do down you can look across the canyon to the folks going down the old one. It's fun and not bad at all, just gear down to save your brakes. We've stayed at Yosemite Lakes, nice park.

It's steep but the "new side" was newly paved in April of 2012 when we did it in our Truck Camper. Plenty of turn outs but sometimes you can't see what's coming around the curve at you and you hope the other guy stays in his lane. If I did it again I would dump the gray and the black tanks and NOT fill that 60 gal fresh water tank full. I would NOT fill fuel tanks fuel either. There's stations at the top. I'd caution you to watch your engine temp gauges and not use your a/c while you tugged up the grade. There is a very nice transmission repair place at the top of the grade and they do a nice job putting in the cooling unit in series on a 1999 F-350. Transmission oil on the hot exhaust pipe does look like you're on fire but it's really all smoke. No need to grab that fire extinguisher and dive underneath, really.Don't be afraid of it - You're smart to ask quesitons before you get there. I did not.

Interesting enough...I have been up old priests grade more times than I can count and honestly would not have a problem(from a power perspective) trying the run up it with my TT and F-150 Ecobeast. I am not sure I would be able to make some of the turns. That being said, I think it defies good sense to actually try Old Priests grade with a TT for two reasons: 1. I can only imagine how much fuel I would use going up it. I would prob just watch the gas gauge drop as the turbos sucked the fuel. 2. It seems to me to be stupid to put that much unnecessary wear and tear on a vehicle if you don't have too assuming you can actually make all the curves.There is no way in heck I would even think about going down Old Priests grade with an F-150 and a TT. I appreciate the feedback since we just recently got into the TT/RV thing. We have not made very many trips let alone on those kinds of grades. The advice is well taken.

jbbrick wrote:Make sure you take the newer side, not the "old" Priest Grade. You won't have any problem at all, I did it not long ago with my 32' MH pulling a car. As you do down you can look across the canyon to the folks going down the old one. It's fun and not bad at all, just gear down to save your brakes. We've stayed at Yosemite Lakes, nice park.2x on not going off on the right side where the old/new Priest run divide like we did. We made it in our 1992 32' P30 based MH in 2011 but it was pedal to the metal doing 15 MPH in first gear for four very long miles with the temp gauge 3 hairs from the red zone. We would have been in a heap for trouble had one plug wire failed or the cooling system had not been only five years old I expect. We went out the Fresno side which is a piece of cake way in and out.

I will drive up the Old Priest Grade with my camper on my truck, as it saves some driving time following the new road. However, I won't drive down it.Bob in Calif.

Priests Grade in California | Good Sam Community

katleman
Explorer
Aug 14, 2013
Did Sonora pass for the first time last summer, in a car. Incredibly scenic, but the grades are outrageous, makes Tioga, Beartooth, etc, look like flat roads. Would never attempt it in an RV.

As to Old Priest grade, its my favorite part of thr drive to and from Yosemite each year. fun to drive in a non RV, and saves 5 miles each way.

Have taken New Priest grade several times in a RV, no problems at all, likewise with Tioga pass.
jbbrick
Explorer
Aug 13, 2013
I'd avoid Sonora at all costs when towing especially East to West. You're up at several thou feet already with low power, and there is one hill where you make a sharp right turn and can't get the rev's up. You'll be crawling in low gear-we did it a long time ago in a car and tent trailer and I could have walked up faster than we drove, floored in low gear. Did it again in the MH a few years ago and it was the same slow crawl, flat out in low. Tioga is a breeze plus really a beautiful ride but you have to pay for park access.
jefe_4x4
Explorer
Aug 12, 2013
Tioga is a LOT easier than Sonora. The east side of Tioga is pretty steep, but a lot less grade than Sonora. On the east side, Sonora Pass Rd. I was in 2nd gear much of the time (in a 6 spd. manual) and tried to up shift a couple times and the grade brought that Cummins 6BT with 505 pound feet of torque, turbo a-whinin', right down to it's knees.
jefe
Gale_Hawkins
Explorer
Aug 12, 2013
Sure not a MH friendly pass. :)
coolbreeze01
Explorer
Aug 11, 2013
Some good pics here Sonora Pass. Enjoy :C
aussy
Explorer
Aug 11, 2013
I never thought of Sonora pass. How is Tioga pass in comparison?
jefe_4x4
Explorer
Aug 11, 2013
We've been up and down Priests Grade many a time on our way to Yosemite. However, there is a sign which either restricts or gives a gross weight and length restriction on the 'old road', and it's pretty low, like 9000 or 10000 pounds. Our TC is only 20 feet in length but over 10000 lbs. so we always take the 'high road' with the other overweight rigs.
The worst grade i've seen in CA is State Route 108 which goes over Sonora Pass and has some stretches of 24 to 30% grade. Many an automatic trannie has met its demise on this paved over cow path.

regards, as always, jefe
louiskathy
Explorer
Aug 11, 2013
Yep, driving at a higher RPM would have forced more air through the transmission cooler and we would not have blown a seal on the tranny. Wish we had known THAT before we went up Priest's grade.

While we were cooling down and letting that seal reset... I managed to get on the internet and RV.NET guys gave some great info and advice. That was to ADD a cooling unit in series (instead of just replacing the one we had with a larger one.) Put them side by side. GREAT advice for us. That's what we had done the next morning.
Gale_Hawkins
Explorer
Aug 10, 2013
Up I like to be at 3500+ RPM

Going down I like max RPM at or blow WOT take off shift up point where no braking is required. After you spend an hour on the grades you should have the feel.
aussy
Explorer
Aug 10, 2013
My F-150 has a 6 speed auto. Going up, would you guys recommend putting it a fixed gear maybe 3rd or 4th or just let the auto transmission decide?

Than going down, in a fixed gear? If so, what is the rule for putting in a fixed gear?