Well I'm phukd. Th400 lost 3rd

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.

Jrgunn5150

Questionable methods
Joined
Jan 11, 2016
Posts
2,739
Reaction score
1,412
Location
Ionia Mi
First Name
J.R.
Truck Year
1979
Truck Model
C10
Engine Size
6.slow
The only thing I'd do in way of modifications if the hard parts are good is dual feed the direct clutches. I'd do it internally while rebuilding and not via VB plate.
 

da_raabi

Trailer Park Supervisor
Joined
Aug 7, 2013
Posts
1,403
Reaction score
901
Location
FloriDUH
First Name
Adam
Truck Year
1986
Truck Model
c30
Engine Size
454
I agree. The B&M Shift Improver kit is junk. Nothing but a crude way to increase line pressure for VERY hard shifts that pound the drivetrain. The TransGo 350-1-2 kit is light years better, which is why it has been used by rebuild shops for at least 35 years to reduce clutch wear and "come backs". It also includes detailed instructions with good pictures. But unless you want super-firm shifts, do just the Level 1 mods, which will give you firmer shifts than stock, but not harsh.

That's my plan. The Transgo 400-1-2 kit is pretty cheap on eBay. Most places list it for $90+, eBay has it for $69.
 

da_raabi

Trailer Park Supervisor
Joined
Aug 7, 2013
Posts
1,403
Reaction score
901
Location
FloriDUH
First Name
Adam
Truck Year
1986
Truck Model
c30
Engine Size
454
The only thing I'd do in way of modifications if the hard parts are good is dual feed the direct clutches. I'd do it internally while rebuilding and not via VB plate.

I was curious about that. I know you can do some internal modifications, but how would they interact with a shift kit like the one from Transgo?

Check out the attached PDF I made of an old Jake's Performance tech article.
 

Attachments

  • TH400_Rebuild_Tech.pdf
    625.5 KB · Views: 206

74 Shortbed

Full Access Member
Joined
Aug 12, 2013
Posts
6,306
Reaction score
1,411
Location
*
First Name
*
Truck Year
*
Truck Model
*
Engine Size
*
The Transgo kit is a "Reprogramming" kit, let's you start out in any gear and it stays there until you shift it, also let's you downshift at any speed into any gear, if that don't interest you save the money and just do the "dual feed" and drill out the feed holes and you'll have firm 1-2 and 2-3 shifts.
 

Jrgunn5150

Questionable methods
Joined
Jan 11, 2016
Posts
2,739
Reaction score
1,412
Location
Ionia Mi
First Name
J.R.
Truck Year
1979
Truck Model
C10
Engine Size
6.slow
I was curious about that. I know you can do some internal modifications, but how would they interact with a shift kit like the one from Transgo?

Check out the attached PDF I made of an old Jake's Performance tech article.


Transgo does the same thing with a plate between the VB and the case. My issue is that it can leak internally and not function properly. I prefer to just make the internal change and be done with it.

The TH400 is dual fed with the holes drilled larger like Mike said, and is happily doing rolling 50 mph burnouts with roughly 500 whp.

Since you're rebuilding anyway, you can make the internal changes while you're in there. REally no reason to blow the extra cash on a shift kit.
 

MikeB

Full Access Member
Joined
Apr 4, 2014
Posts
1,748
Reaction score
936
Location
North Texas
First Name
Mike
Truck Year
1969
Truck Model
C10
Engine Size
355
I get calls from people telling me they need a reverse torx special socket. No you don't it's just a common 12pt 3/8.
Reverse torx socket??? Those folks need to turn slowly and walk away from the project.:eek:
 

MikeB

Full Access Member
Joined
Apr 4, 2014
Posts
1,748
Reaction score
936
Location
North Texas
First Name
Mike
Truck Year
1969
Truck Model
C10
Engine Size
355
Just want to say I am learning a bunch here about auto transmissions. All my comments above are from a novice's perspective. As I mentioned in another thread, I'd really like to find an 1988-up 700R4 and go through it to use in my truck, but looks like that would require several expensive tools, right? I'd also be open to a 2004R, which would handle all the power I'd ever need it to.
 

Honky Kong jr

Super Sarcastic Man
Joined
Jun 14, 2016
Posts
14,968
Reaction score
9,789
Location
Denver,PA
First Name
J-me
Truck Year
87
Truck Model
V10
Engine Size
Lil BB 407
And don’t use Dextron. My automatics get Type F and have for years.
 

da_raabi

Trailer Park Supervisor
Joined
Aug 7, 2013
Posts
1,403
Reaction score
901
Location
FloriDUH
First Name
Adam
Truck Year
1986
Truck Model
c30
Engine Size
454
What stall should I be looking at in a converter? The truck is a basically-stock 454 dually with 4.10s out back. 2wd. Would 2000 be too high? I'm trying to find a cheapie converter, but they get expensive fast when you drop below 2000.
 

Jrgunn5150

Questionable methods
Joined
Jan 11, 2016
Posts
2,739
Reaction score
1,412
Location
Ionia Mi
First Name
J.R.
Truck Year
1979
Truck Model
C10
Engine Size
6.slow
What stall should I be looking at in a converter? The truck is a basically-stock 454 dually with 4.10s out back. 2wd. Would 2000 be too high? I'm trying to find a cheapie converter, but they get expensive fast when you drop below 2000.


You can try one from a 6.2 truck, or spec'd for a 6.2 diesel for a budget low stall.
 

da_raabi

Trailer Park Supervisor
Joined
Aug 7, 2013
Posts
1,403
Reaction score
901
Location
FloriDUH
First Name
Adam
Truck Year
1986
Truck Model
c30
Engine Size
454
Well right now I'm looking at 2 different converters, both stock remans from Dacco. The first is a TH400 model with a 1200-1400 stall, the other is a TH350 model with a 1700-1900 stall. Thoughts on going to a slightly higher stall? Price is about the same on RockAuto. About $60 after core return (not bad!!).
 

CSFJ

-----------------
Supporting Member
Joined
Jul 1, 2014
Posts
6,160
Reaction score
5,162
Location
------
First Name
-------------
Truck Year
-------
Truck Model
-------
Engine Size
-------
Isn't there a difference on the bolt pattern to the flex plate between the 350 and 400, or am I mis-remembering?
 

da_raabi

Trailer Park Supervisor
Joined
Aug 7, 2013
Posts
1,403
Reaction score
901
Location
FloriDUH
First Name
Adam
Truck Year
1986
Truck Model
c30
Engine Size
454
Isn't there a difference on the bolt pattern to the flex plate between the 350 and 400, or am I mis-remembering?

Yes, there are two different bolt patterns. I think the TH400 converters use an 11.5" (approx) pattern while the TH350 uses a 10.75" (approx) pattern. I had to deal with this when I was trying to put a TH350 behind a 454 in my Camaro. Summit sells a real nice flexplate that has both bolt patterns for about $50. Its even SFI approved and made in USA.

I needed a new flexplate anyway since the original got chewed up by a broke-ass starter. So I can use whatever converter I want.
 

CSFJ

-----------------
Supporting Member
Joined
Jul 1, 2014
Posts
6,160
Reaction score
5,162
Location
------
First Name
-------------
Truck Year
-------
Truck Model
-------
Engine Size
-------
Gotcha. Didn't know if you had the dual pattern flexplate already.
 

Jrgunn5150

Questionable methods
Joined
Jan 11, 2016
Posts
2,739
Reaction score
1,412
Location
Ionia Mi
First Name
J.R.
Truck Year
1979
Truck Model
C10
Engine Size
6.slow
Well right now I'm looking at 2 different converters, both stock remans from Dacco. The first is a TH400 model with a 1200-1400 stall, the other is a TH350 model with a 1700-1900 stall. Thoughts on going to a slightly higher stall? Price is about the same on RockAuto. About $60 after core return (not bad!!).


I'd need to know the specs on your engine, cam, gear ratio, tire size, usage, before I could really get into pro's and cons of each converter.
 

Latest posts

Forum statistics

Threads
42,076
Posts
908,507
Members
33,550
Latest member
kurt54
Top