TH400 seems to be dragging

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Old60Driver

1983 K20 Silverado
Joined
May 17, 2020
Posts
245
Reaction score
306
Location
Houston
First Name
Michael
Truck Year
1983
Truck Model
K20 Silverado
Engine Size
350
Are we talking about letting off in third gear at 65 or 70 miles an hour, or does it feel like it is dragging even at low RPM?

In a newer truck with a six, eight or 10 speed transmission they have double and triple overdrives. So even when you let off at freeway speed that top gear is only turning the engine at ~1300rpm or less...

Well, I haven't actually run her up past 60 or so, but I really notice it above 45 or so...
 

83Burban

Full Access Member
Joined
Apr 10, 2021
Posts
207
Reaction score
268
Location
Kansas CIty, MO
First Name
Matthew
Truck Year
1983
Truck Model
Suburban K10
Engine Size
454
Well, I haven't actually run her up past 60 or so, but I really notice it above 45 or so...

This may seem silly....but are you 100% sure you dont have a break dragging?

And 60mph at 2500 seems right-ish if you are running stock wheels and tires. Should be 215/85/16 right (30ish")?

Where in KS you at? My lady is from SE Kansas and im down there pretty frequently of you need a hand. Or even just want to compare what you are feeling to my square.
 

Old60Driver

1983 K20 Silverado
Joined
May 17, 2020
Posts
245
Reaction score
306
Location
Houston
First Name
Michael
Truck Year
1983
Truck Model
K20 Silverado
Engine Size
350
This may seem silly....but are you 100% sure you dont have a break dragging?

And 60mph at 2500 seems right-ish if you are running stock wheels and tires. Should be 215/85/16 right (30ish")?

Where in KS you at? My lady is from SE Kansas and im down there pretty frequently of you need a hand. Or even just want to compare what you are feeling to my square.

I had to put new tires on her as soon as I started tinkering on her and decided that I wanted something with just a touch more meat on them. The stock tires were 235/85/R16 and I went with 285/65/R16. It made a nice difference, and it should have only made a few mph difference on the speedo. Interestingly, my GPS shows it to be spot on now...

When I changed the tires, I pulled the rear drums off and gave them a good cleaning with brake cleaner, and slapped her back together. Did the same for the discs in the front. Didn't notice any drag at the time, but I'll pop her up on the jack this morning and see what tales she has to tell me.

I'm actually working in Enid, OK. Travelled up to there from Houston, but my truck is up in Hutchinson, KS. I'm actually going to be driving her back to Enid today! Her first real trip in a decade or two! And thanks for the offer, I may just take you up on that!!

View media item 9482View media item 9481
You must be registered for see images attach
 

Latest posts

Forum statistics

Threads
44,414
Posts
956,959
Members
36,736
Latest member
bartram89
Top