RustyC
Well-Known Member
- Joined
- Dec 15, 2010
- Messages
- 1,251
Looking for a little input. I am looking into re-gearing my tow rig after installing larger tires. The truck is a 2002 F250 cc, srw 7.3/auto/4x4. The truck originally had 265/75/16 tires. It now has 315/75/16 tires.
With the 35" tire and 3.73 gear it needs a little help in the gearing. Truck has an 4r100 transmission. Truck pulls a 20' enclosed that weights about 10klbs plus. I find myself towing in 3rd gear/OD off.
My converter does not lock in 3rd and I'm concerned about towing in 4th. The converter does lock in 4th gear.
I am looking at a couple of options on re-gearing. It is splitting hairs but still looking for input. I am looking into a 4.10 or 4.30 ratio gear. The 4.10 put me back to the factory gearing with the 35"s.
I only use the truck to tow and occasionally on the weekends. The truck does have a TS 6 position chip,4" exhaust, gauges and extra trans cooling. Injectors are stock but will be upgraded with one size larger and the chip reflashed.
I have no desire to stress this engine with big turbos, BIG injectors etc. Goals after injector upgrade in 350hp and low exhaust temps. I'm not sure it the trans can be tuned to lock in 3rd over 45 mph but I would love that if possible.
I am leaning towards the 4.30 ratio because its a 7700 lb truck on larger tires and doesn't need to be running over 75 anyway and I'm getting older so...
If anyone has any similar experience or advice on gearing, towing in 3rd vs 4th on a 4r100 trans, lets here it.
With the 35" tire and 3.73 gear it needs a little help in the gearing. Truck has an 4r100 transmission. Truck pulls a 20' enclosed that weights about 10klbs plus. I find myself towing in 3rd gear/OD off.
My converter does not lock in 3rd and I'm concerned about towing in 4th. The converter does lock in 4th gear.
I am looking at a couple of options on re-gearing. It is splitting hairs but still looking for input. I am looking into a 4.10 or 4.30 ratio gear. The 4.10 put me back to the factory gearing with the 35"s.
I only use the truck to tow and occasionally on the weekends. The truck does have a TS 6 position chip,4" exhaust, gauges and extra trans cooling. Injectors are stock but will be upgraded with one size larger and the chip reflashed.
I have no desire to stress this engine with big turbos, BIG injectors etc. Goals after injector upgrade in 350hp and low exhaust temps. I'm not sure it the trans can be tuned to lock in 3rd over 45 mph but I would love that if possible.
I am leaning towards the 4.30 ratio because its a 7700 lb truck on larger tires and doesn't need to be running over 75 anyway and I'm getting older so...
If anyone has any similar experience or advice on gearing, towing in 3rd vs 4th on a 4r100 trans, lets here it.