Do You Cover Your Vertical Exhaust Stack Tip While Trailering?

[Utopia Texas]

I've owned and driven dozens of tractors in my 61 years and tonight read something in the manual of my NH T4.75 that I had never seen before. The manual says to cover the end of the vertical exhaust stack when trailering the tractor so air/wind does not travel down the exhaust system and spin the turbine which is not being lubricated with the engine off. Has anyone ever burned out the bearings on their turbine set up by not following these instructions? This is a new one on me !

 

[DT86]

I've heard of it but don't know anyone it has actually happened to.

I passed a load of New Hollands headed to a dealer the other day and don't remember seeing the stacks having covers.

 

[tow653]

We moved lots of tractors between Missouri and Louisiana,and always covered the exhaust pipe,to prevent the turbo from spinning without lubrication. Note,it only applies if tractor is turbo charged.

 

[big bubba]

you'll get a lot of controversy on this. called "pinwheeling", the idea being the turbo is being rotated (due to vacuum) while being transported & not in operation & w/o lubrication. will be interesting to see what advice you get here. it is an old school practice to plug it up in transit. an old sock will do.... when i park outside in the open i cover the stack with something to keep the moisture out...just an old practice. hey ask a seasoned trucker on this one....

 

[Industrial Toys]

Someone told me that the turbo does not even have bearings. Somehow it spins in oil. So I am told.

I cover the stack, just in case. I mean, no big deal.

But I wonder, where can the air go? You need air flow to make the turbo spin.

 

[5030]

Turbochargers have ceramic bearings/seals on the hot side and conventional bearings on the cool side fed with pressurized oil.

I've never covered mine up when transporting on the low boy with no issue. If it sits outside (rarely) in the rain, I cover the stack so when I start it, it don't blow black soot all over the hood.

 

[big bubba]

Someone told me that the turbo does not even have bearings. Somehow it spins in oil. So I am told.

I cover the stack, just in case. I mean, no big deal.

But I wonder, where can the air go? You need air flow to make the turbo spin.

vacuum is created in this situation (while being transported) & the turbine will spin, doesn't have to be an inlet/outlet for that to happen

 

[MHarryE]

In theory the air must have some place to pass through. Usually only an exhaust or an intake valve is open but the top of the exhaust stroke is the start of the intake stroke so briefly there is a valve overlap that will allow air passage. However this also holds true for parking your tractor outside if it is windy. On a truckers forum, one trucker said the bill of lading for one manufacturer states the exhaust must be covered. Can't remember which company that is. Another said he had a turbo show failed when the tractor was unloaded but was fine when he loaded it at a factory so his insurance had to pay for the replacement. Yet another trucker said he didn't think it was possible but why take a chance. He keeps a stock of Nerf footballs in his cab. If he forgets the exhaust blows the football out of the stack when the engine is started. Our John Deere dealer claims they have a valve that prevents turbo damage. Not sure what that would be unless it is an anti-bleed off valve that keeps oil in the turbo bearing area when the engine is shut down.

 

[Utopia Texas]

Someone told me that the turbo does not even have bearings. Somehow it spins in oil. So I am told.

I cover the stack, just in case. I mean, no big deal.

But I wonder, where can the air go? You need air flow to make the turbo spin.

My manual actually uses the word "bearings" but who knows?

 

[big bubba]

this is going to be an interesting thread. nerf footballs so far is my favorite answer....