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RedBed · 08-04-2017, 07:41 PM

A friend is swapping out a 4L60 for my TH350 currently. He has run into an issue and having trouble finding info on it. And I hope I can describe the problem correctly (since I don't know SQUAT about transmissions or speedo gears).

He has the transmission installed. It is working fine, but he says the Speedometer is about 10mph fast. He thinks he will need to change the gear on the Output shaft (?) on the transmission side, but would like to know the correct gears on both ends.

The guy who is working on the truck is a master with transmissions, but he's really stumped by this one. Any ideas or any sources of info that might help?

THANKS!

08-04-2017, 07:41 PM	#1
RedBed Registered User Join Date: Apr 2017 Location: TX Posts: 257	Speedometer Gears A friend is swapping out a 4L60 for my TH350 currently. He has run into an issue and having trouble finding info on it. And I hope I can describe the problem correctly (since I don't know SQUAT about transmissions or speedo gears). He has the transmission installed. It is working fine, but he says the Speedometer is about 10mph fast. He thinks he will need to change the gear on the Output shaft (?) on the transmission side, but would like to know the correct gears on both ends. The guy who is working on the truck is a master with transmissions, but he's really stumped by this one. Any ideas or any sources of info that might help? THANKS! __________________ *1979 Chevrolet Bonanza/305/4L60/Edelbrock Performer/Holley 600 Classic* Last edited by RedBed; 08-06-2017 at 11:21 PM.