PDA

View Full Version : Tire Pressure?


6ballsisall
05-01-2006, 11:51 AM
What do you keep your tire pressure at on your boat trailer?

I keep mine @ 40psi but they always look like they are flat??? I know visuals aren't what you want to go of off but they just seem to low.

Footin
05-01-2006, 11:54 AM
Goodyear Marathons say to keep at 50 psi cold. I keep mine close to 50.

skitilldark
05-01-2006, 11:58 AM
I also keep mine around 50.

east tx skier
05-01-2006, 12:17 PM
50 here, too.

jraben8
05-01-2006, 12:27 PM
50, 50 and 50 in the spare.

Leroy
05-01-2006, 12:43 PM
What is the recommended pressure on your tires?

TMCNo1
05-01-2006, 12:47 PM
Just remember to use more air pressure in your tires, than you put in your blow-up doll. Your tires have more riding on them!

Diesel
05-01-2006, 01:41 PM
Always inflate to MAX pressure on trailer tires.

6ballsisall
05-01-2006, 01:44 PM
Thanks all, I will do. IIRC, the tires say Max pressure of 55psi cold. I'll crank them up. I dont remember the tire size off hand but they are 14" wheels. I was a little surprised the local MC dealer didn't have or have access to a spare tire for my trailer. I didn't even care if it was the same wheel design. Guess based on my last experience I shouldn't be surprised :rolleyes: (Yes that was a cheap shot, yes I am still pissed off!! :mad: )

Tom023
05-01-2006, 01:45 PM
Always inflate to MAX pressure on trailer tires.

And, check them while they are cold.

Tom023
05-01-2006, 01:46 PM
A bit of a threadjack but related, what should the lug nuts be torqued to?

Diesel
05-01-2006, 01:53 PM
A bit of a threadjack but related, what should the lug nuts be torqued to?

Depends upon the size of the thread. I belive most MC trailers run 1/2" threads. Remember overtight is just as bad as undertight........


Stud Size Torque in Ft/Lbs

10MM 45-55
12MM 70-80
14MM 85-90
7/16" 70-80
1/2" 75-85
9/16" 135-145
12x1.5mm 6.5
12x1.25mm

Tom023
05-01-2006, 01:59 PM
Thanks Diesel !!!

east tx skier
05-01-2006, 04:24 PM
Thanks all, I will do. IIRC, the tires say Max pressure of 55psi cold. I'll crank them up. I dont remember the tire size off hand but they are 14" wheels. I was a little surprised the local MC dealer didn't have or have access to a spare tire for my trailer. I didn't even care if it was the same wheel design. Guess based on my last experience I shouldn't be surprised :rolleyes: (Yes that was a cheap shot, yes I am still pissed off!! :mad: )

Tire size is 215 75 R14 IIRC. Wheels are 5 lug, 4.5" bolt pattern x 6". Correct me if I'm wrong.

P-hat_in_Cincy
05-01-2006, 05:14 PM
Sort of a threadjack, but kind of not. I'm pretty sure you should go by the tire pressure listed on the placard and not necessarily what's listed on the tire. Same for vehicles. Basically, the placard says "this 'vehicle' was designed to run (this) tire at (this) pressure."
Correct me if I'm wrong.

east tx skier
05-01-2006, 05:18 PM
That's what I've always heard for cars and trucks. I haven't looked at the trailer manual in a while to see if it's listed in there. My placards on the trailer aren't too much of the legible variety. :)

Workin' 4 Toys
05-01-2006, 11:43 PM
What do you keep your tire pressure at on your boat trailer?

I keep mine @ 40psi but they always look like they are flat??? I know visuals aren't what you want to go of off but they just seem to low.
Mine are at 50.

1984StarsandStripes
05-02-2006, 12:11 AM
Anybody running Aluminum rims? I have the chance to get a deal on a set of three for my '84 with brand new rims, rubber, lugs and center caps fr 70 bucks a piece. They are for a buddy whose friends runs a trailer customizing shop and they are takeoffs for the factory. Any thoughts, little concerns about weight what they are trailer rims and tires.

Workin' 4 Toys
05-02-2006, 12:18 AM
Mine are aluminum.

JimN
05-02-2006, 12:35 AM
IIRC, we were told to tighten the nuts in three steps 75 ft/lb, 90 ft/lb and then 105 ft/lb. Anti-seize on the threads.

Will or MYMC- help me out here!

1984StarsandStripes
05-02-2006, 09:31 AM
Mine are aluminum.

Single or double axle trailer? I have an '84 single axle

Kevin 89MC
05-02-2006, 09:41 AM
The psi on the tire sidewall is the MAX allowed by the tire manufacturer. It is also what is needed to carry the maximum load allowable by the tire. The "placard" is what is recommended by the vehicle. I can't read the placard on my trailer anymore. Going over (or under) the recommended pressure can change driveability characteristics. You do need to know what you're doing, and what to expect. I run 50 psi because I'm more concerned about the tire's ability to handle a heavy load and maximum life of the sidewall, than I am concerned about having the smoothest ride. I do keep an eye on treadwear, though. If it starts wearing in the center, then I'll back off the pressure a bit.
As far as torque, for steel I put them on "pretty tight" with the lug wrench. For aluminum, I go "a bit less". I've occasionally checked them with a torque wrench, and I'm usually pretty close to specified torque.

FrankSchwab
05-02-2006, 11:00 AM
JimN -
The current trailer manual lists 45, 70, and 90 as the three torque steps.

/frank

NSXBill
05-02-2006, 12:23 PM
FWIW, the current single-axle trailers use 15" six lug wheels with Marathon 225-75-15 tires of the load range D variety. Its a pretty big tire with a Max pressure of 65 psi for the D range. (I think C range Marathons are available in this size and have a much lower max pressure (50-55). Max pressure should generally be used when the tires are seeing their maximum weight (which hopefully we are all below). Anything below that should use less pressure. Its all about having an even contact wear patch (except SUVs and rolling over). I've been using 60-62 psi.

Very interested in the torque b/c I am in the process of acquiring a spare (Tire from Walmart $91, wheel from local shop $85).

YMMV

Thrall
05-02-2006, 01:00 PM
Sort of a threadjack, but kind of not. I'm pretty sure you should go by the tire pressure listed on the placard and not necessarily what's listed on the tire. Same for vehicles. Basically, the placard says "this 'vehicle' was designed to run (this) tire at (this) pressure."
Correct me if I'm wrong.

That's true in some cases. Depends on the application. Trailer tires, I've always been told to run them a t max tire pressure. SOft tires generate heat and that's bad for any tire, especially trailer tires, I think because the old ones used to be bias ply for stiffer sidewalls and the new radial trailer tires also have stiffer than avg (car) sidewalls.
Now if you're hauling a 3000# total weight with tires that are way over rated for the application, it may not hurt to run less than max psi.
Looking at light trucks, 3/4 ton, the placard on the vehicle will show pressure reccomendations for max gvw. If a Load range E tire is on the back of an empty truck, it doesn't need 80 psi. WOn't hurt anything, but will ride like a lumber wagon. My 3/4 ton, when empty, I run 55psi front (diesel=heavy front end) and 45-50 psi rear. If I was going to put alot of weight on the bed/trlr hitch, I'll air them up to max 80 psi.
Passenger cars that don't have a huge swing in GVW day to day, are usually fine to run at reccomended pressure for stock type tires.

NSXBill
05-03-2006, 10:41 AM
JimN -
The current trailer manual lists 45, 70, and 90 as the three torque steps.

/frank
I looked through all my boat stuff last night, and I don't have a trailer manual. I don't think it ever came with one. I have the manuals for all the trailer stuff like brakes, etc, but no manual for just the trailer.

Any more info on torque spec for 6-lug (1/2" studs) 15" aluminum wheel?