Questions about the Precept Specs

[Larry Mac]

I see that the v-10 is used in all the Precepts. From the 31' to the 36'. I'm interested in the 36t ( two bathrooms). The 31' and 35' weigh 22k #, yet the same V-10 is used in the 36t which weighs 24k#. Doesn't it seem that the 36t would be sluggish and underpowered?

Also this was on their website as well as the Precept brochure I picked up at the Tampa RV show.
The wheel base of the 31' which is actually 32' and the 36t which is actually 38' is listed as the same--190 inch. How can that be? Btw the wheelbase for the 35' is 228 inch. I'm sorry I didn't notice this at the show to ask the owners there. I called Jayco yesterday and talked to someone who didn't know but took my number and said he would call back with the info.


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[Jopopsy]

I was looking at the specs on those a while back; I was quite surprised that the wheelbases on these rigs are so short. Rule of thumb says 55-56% wheelbase ratio leads to a steadier drive on the highway. Some of these rigs show a much shorter ratio then my Greyhawk.

I don't understand it.

I'm just north of 57%. I had a 'C' w/ a 53%. There's a difference.

[NickM]

Hi Larry,

Nice conversation today, look forward to meeting you in person.

I wonder if the wheelbase differences are typos in the marketing specs? Let me know what you find out.

Maybe the 36T uses different gearing in the drive train? Or maybe Jayco buys a standard F53 package from Ford and the 24k is max for the engine and drive train? Might check on IRV2 forum, lots of F53 users show up there.

I am considering a V10 tuner module for mine later in the year. If we are fortunate enough to tour the West I think it will make the mountains more tolerable.

I've said this before, why doesn't Ford offer their 6.7 diesel in the F53 chassis? Had this engine in an F350 and F450 and believe it would be a great match for the F53. Couple that to the 6 speed auto/manual tranny and I'd think any manufacturer would have a winning package. Just sayin'.

[StevL]

The 31ul is 190" wheelbase, i think the 36t at 190 is a typo. Call Jayco or a dealer.

Steve

[Jopopsy]

Originally Posted by StevL

The 31ul is 190" wheelbase, i think the 36t at 190 is a typo. Call Jayco or a dealer.

Steve

That's a 49% wheelbase, meaning 1/2 your rig is hanging behind your rear tires. How's the handling on yours? From what I've read your front end should be easy to unload the weight off the tires ... but again its only what I've read. I know my shorter wheelbase Class 'C' (a 32' Winnie) had very poor handling characteristics.

The wider wheelbases make for tougher maneuvering in close quarters, but more equitable weight distribution between the tires and easier driving on the highway since there is more natural bias towards putting some weight on the steer axle.

I'd love to know why they put a 223" wheelbase on my 32' C and a 190" wheelbase on your 32' A. Overhang is overhang, weight is weight.

[Jopopsy]

I found this: https://www.fmcmagazine.com/back-iss...cept-31ul.html

Seems like the Jayco suspension upgrades contribute a great deal to the handling on it. Perhaps its able to mask the narrow wheelbase. Looks like it drives very well. I just wonder why they didn't stretch the base out a little anyway.

[StevL]

I would say my handling was not what I would have liked box stock on delivery. Any speed near 65 you certainly had to pay attention, at 70 is was two hands on the wheel and giving it your complete attention. Speeds above that were flat dangerous.

Loading the coach with personal items and paying attention to keep heavier items in the most front bays, adjusting tire pressure to 94 psi all the way around, and adding a Safe T Plus I now feel very comfortable cruising at 70. On nice stretches of interstate I'll move along at 70 with no problems while towing.

Could it still be better? Probably, but I'm good with it now.

I think the entire F53 chassis needs a major upgrade, this ladder chassis has been used for years with hardly a change. Technology today is far better than this design.

BTW; I've heard the 2017 with the larger tires handled better than the older models. I would like to hear it from the horses mouth, anyone?

Steve

[Larry Mac]

I received the info necessary from a dealer who got it from his Jayco Rep. I had spoken with a gentleman named Paul at Jayco on Monday, who has not called me back yet.
Anyways like Nick had mentioned above, the 38t has a different axel ratio allowing it to handle the bigger load with the same V-10.
Also evidently I was the first to call about the wheelbase length. And indeed there was a typo, the wheelbase length was not 190" but actually 249". So Jayco will be correcting their website, but too late for the thousands of brochures handed out at the Tampa show. LOL That will give it a .546 ratio.

[Jopopsy]

This isn't the first time I've heard about typos on the Jayco spec sheets online. They do a pretty poor job in that regard, IMHO. If you're going to post the specs out there, you should make sure they're correct. These 'pleasure' purchases don't come cheap.

[StevL]

Originally Posted by Jopopsy

This isn't the first time I've heard about typos on the Jayco spec sheets online. They do a pretty poor job in that regard, IMHO. If you're going to post the specs out there, you should make sure they're correct. These 'pleasure' purchases don't come cheap.

+1



Steve

[greg449]

Originally Posted by StevL

I would say my handling was not what I would have liked box stock on delivery. Any speed near 65 you certainly had to pay attention, at 70 is was two hands on the wheel and giving it your complete attention. Speeds above that were flat dangerous.

Loading the coach with personal items and paying attention to keep heavier items in the most front bays, adjusting tire pressure to 94 psi all the way around, and adding a Safe T Plus I now feel very comfortable cruising at 70. On nice stretches of interstate I'll move along at 70 with no problems while towing.

Could it still be better? Probably, but I'm good with it now.

I think the entire F53 chassis needs a major upgrade, this ladder chassis has been used for years with hardly a change. Technology today is far better than this design.

BTW; I've heard the 2017 with the larger tires handled better than the older models. I would like to hear it from the horses mouth, anyone?

Steve

I drove my brand new 2017 31UL home last night. Probably the biggest change with the 2017 model is that they moved from a 18,000 pound to a 22,000 pound Ford chassis. Included with that was changing the tires from 19.5 inch to 22.5 inch. I believe this will prove to be a very positive change and I'm so glad I waited instead of buying a 2016 model.

Happy Trails!

[StevL]

Can someone tell me for certain the 22k chassis comes from more than changing to the 22.5" tires? The load rating of the tires is much higher than the 19.5" and the chassis still has 190" wheel base. I'm just not certain it's a tire change.

Steve

[NickM]

Originally Posted by StevL

BTW; I've heard the 2017 with the larger tires handled better than the older models. I would like to hear it from the horses mouth, anyone?

Steve

What size are your tires Steve? Mine are the 22.5" Michelin and are at the placarded pressure. I had new valve stems installed during the last warranty round and he set the pressure back to the Jayco sticker. I had them at 100 psi on our first road trip of 400 miles and thought it drove pretty good.

[Vicr]

The 22k chassis comes with the 22.5 wheels as well as a different differential that is geared lower. All the chassis specs can be found on line from a Ford PDF file. Google " Ford F53 Chassis".

[Jopopsy]

Originally Posted by Vicr

All the chassis specs can be found on line from a Ford PDF file. Google " Ford F53 Chassis".

That won't take into account any chassis stretching or other modifications that Jayco subcontracts out to Mor-Ryde.

[Cycledoc675]

The stock 18K F53 with 19.5" tires handles and rides very well on my 2015 29UM. However, I suspect that the floorplan and weight distribution on my now discontinued model was more favorable than the 31UL prior to 2017 built on the 18K chassis. I saw a friend's 2017 Thor Outlaw 37RB on the 26K F53 with the 22.5" tires....those tires look huge compared to my rig....hopefully my tires will be cheaper when time to replace.