Either your speedo is wrong or you have 4.55s, I’m at 83 mph in fourth at the same rpm, and 106 in 5th in at the same rpm
How hot do they need to get for this to happen?these trucks need a lot of heat to burn off carbon deposit if they aren’t run hard often.
How hot do they need to get for this to happen?
Either your speedo is wrong or you have 4.55s, I’m at 83 mph in fourth at the same rpm, and 106 in 5th in at the same rpm
Well what the deuce... maybe YOU have airplane gears!Either your speedo is wrong or you have 4.55s, I’m at 83 mph in fourth at the same rpm, and 106 in 5th in at the same rpm
That's for cleaning deposits? Or DEF system? Is this driving or stationary?On the big Cats at work, we try to get the EGT up close to 1,000F for a half an hour. That's measured at the end of the manifold, not right at the head.
I’ve got 3.55 and 33” tires, but the old shop truck had stock sized tires and a 4.10 rear and would bury the speedo in fourth when the clutch wasn’t slippingWell what the deuce... maybe YOU have airplane gears!
I'll jack up one side and figure it out for sure then. If I do have abnormally short gearing maybe that's why reverse with a trailer(especially up hill)doesnt bug me in the ZF like it seems to bug others.
And the speedo works good, I've checked it with a GPS.
Back in the mid 90's, a friend and I had an impromptu race down the highway. He was in his 1989 F250, Ex cab, 4x4, ZF5, 235/85R16 tires. We ran down the highway as fast as we could go. I pulled out and went around him at about 105. My 75 F150, 4x2, C6, powered by a 1971 429 had more top end so I won that race. His truck would run 2100 RPMs at 60 in 5th so I am fairly certain that it had 4.10s in it.I’ve got 3.55 and 33” tires, but the old shop truck had stock sized tires and a 4.10 rear and would bury the speedo in fourth when the clutch wasn’t slipping
Why, yes it does!You must be registered for see images
This is rpms for a zf5, 235/85r16s, and 4.56’s.
Look familiar josh_bear?
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You sir have 4.56 gears lolWhy, yes it does!