TH 350 shifts a bit late...adjustable? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Gray Ghost · 05-17-2006, 07:49 AM

It stays in first and second longer than most I've driven and I was wondering if that's adjustable? I'd rather not take it into a shop if I can avoid it...anyone know how/if I can do it myself?

**dennislbrooks** · 05-17-2006, 08:11 AM

Kinda opposite from what I want but some modulators are adjustable, might check for a vaccuum line leak to it, also you may have to replace the modulator --in expensive--check Summit. There are some trans gurus on this forum.

Longhorn Man · 05-17-2006, 02:43 PM

There's a few things you can do. Pull the vac line off the modulator on the bottom of the tranny, and stick a small flat head screwdriver in there. If you feel a screw head, crank it in to lower the shift point, screw it out to raise the shift point. (I think that's right)
If there is no screw, follow the vac line, see where it goes. If it goes to a ported manifold port, pop it off and put it on a ported vac connection.

farmtruckIII · 05-17-2006, 03:47 PM

Also you can adjust the throttke valve control cable (kick down) contrary to popular belief they have some control over the situation.

Longhorn Man · 05-17-2006, 05:52 PM

not a throttle valve.... that's only on overdrive... just a kick down cable. You get them confused and you can waste ppl's time and money.

The kick down cable, if adjusted too tight, can create this problem, but in all reality, it is pretty hard to accidently do this.

farmtruckIII · 05-17-2006, 07:33 PM

Quote:

Originally Posted by Longhorn Man

not a throttle valve.... that's only on overdrive... just a kick down cable. You get them confused and you can waste ppl's time and money.

The kick down cable, if adjusted too tight, can create this problem, but in all reality, it is pretty hard to accidently do this.

Please excuse my ignorance, on the name of the part.

Longhorn Man · 05-17-2006, 09:51 PM

no...I'm sorry if it sounded cockey...
hell, you brought up a point no one else had mentioned.

jrb71c20 · 05-17-2006, 09:59 PM

i replaced my modulator recently and it advised to adjust it by the bolt on the bracket holding it in...I put it in and loosened it to smooth out the shifting. The best part was, nothing spontaniously burst into flames...lol

Longhorn Man · 05-18-2006, 06:01 AM

that's a new one by me.

Gray Ghost · 05-18-2006, 08:51 AM

Thanks Longhorn Man....I'll try that this weekend.

The TV cable is only on the 2004R & 700R4 4 speed autos....I've had one of each before and hated them with a passion.

Myself · 05-18-2006, 09:04 AM

Actually, the TV cable will be on anything with a lock-up torque converter. Including the 200c, 3sp, and some late model TH350.

Gray Ghost · 05-18-2006, 09:10 AM

Another thing I am not fond of....lock up TC's.

Longhorn Man · 05-18-2006, 04:58 PM

Myself, that is inacurate. There is a kick down cable on the TH200C and on the TH350C, not a throttle valve.

Canadian72GMC · 05-18-2006, 09:46 PM

The kickdown cable is connected to the throttle pressure valve in the valve body, You are both correct.

**VetteVet** · 05-18-2006, 11:06 PM

Here is a website that explains a lot about transmission shifting.
http://yarchive.net/car/transmission.html

Myself · 05-19-2006, 11:19 AM

Quote:

Originally Posted by Longhorn Man

Myself, that is inacurate. There is a kick down cable on the TH200C and on the TH350C, not a throttle valve.

Yes, there is. Now I'm not too sure about the 350C but on the 200C there is NO vacuum modulator. The line pressure is controlled through the detent cable. Just like a 700R4. On a TH350 the kickdown cable controls kickdown into 2nd gear ONLY. I guess that's why they call them Throttle Valve cables instead of kickdown cables.

DangerBoy · 05-19-2006, 12:21 PM

On my TH-350 it will kickdown into 1st. Is that only on some models?

Longhorn Man · 05-19-2006, 02:46 PM

350s will kick inot 1st.
you may have me on the 200... I haven't even seen one since the 80's, and I was a kid back then.

Myself · 05-19-2006, 03:32 PM

Yeah the 200's were kinda junky , but they were ok for lighter, low horsepower applications.

Longhorn Man · 05-19-2006, 03:58 PM

yeah, it was funny when my buddy's chevette tore up a TH200. I couldn't believe it. That thing was so slow it was unreal.

Gray Ghost · 05-19-2006, 04:11 PM

The 'Ill-Fated '86 MCSS' had a 2004R....it was rebuilt when I had the motor out. I bought a 330hp HO 350 roller-cam crate motor [another mistake] and after we got it in and took it out for it's maiden voyage, the tranny tanked on the first shift into second gear. There went $1600.

Before the MCSS I had an S-10 Blazer 4x4 with a 700R4 in it. That rebuild totaled over $600 [in '92].

While the 700's are much better trannys, to this day I destest GM's 4 sp autos from the lowly and vastly cheap 1980's cars and trucks. You could give me one, but I'd have it on ebay before you got back home.

05-17-2006, 07:49 AM	#1
Gray Ghost Senior Member Join Date: Sep 2004 Location: Terrell, TX Posts: 1,967	TH 350 shifts a bit late...adjustable? It stays in first and second longer than most I've driven and I was wondering if that's adjustable? I'd rather not take it into a shop if I can avoid it...anyone know how/if I can do it myself? __________________ Kelly '05 GMC Sierra SLE Z71 Bone stock except for new bed rail caps.

05-17-2006, 08:11 AM	#2
dennislbrooks Senior Member Join Date: Feb 2004 Location: Williamsburg, Ohio Posts: 1,777	Re: TH 350 shifts a bit late...adjustable? Kinda opposite from what I want but some modulators are adjustable, might check for a vaccuum line leak to it, also you may have to replace the modulator --in expensive--check Summit. There are some trans gurus on this forum.

05-17-2006, 02:43 PM	#3
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: TH 350 shifts a bit late...adjustable? There's a few things you can do. Pull the vac line off the modulator on the bottom of the tranny, and stick a small flat head screwdriver in there. If you feel a screw head, crank it in to lower the shift point, screw it out to raise the shift point. (I think that's right) If there is no screw, follow the vac line, see where it goes. If it goes to a ported manifold port, pop it off and put it on a ported vac connection.

05-17-2006, 03:47 PM	#4
farmtruckIII 71 GMC 454/TH400 Join Date: Dec 2005 Location: Blue Mound TX Posts: 214	Re: TH 350 shifts a bit late...adjustable? Also you can adjust the throttke valve control cable (kick down) contrary to popular belief they have some control over the situation. __________________ "The bigger you are the harder you fall, the farther you walk the longer you crawl."

05-17-2006, 05:52 PM	#5
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: TH 350 shifts a bit late...adjustable? not a throttle valve.... that's only on overdrive... just a kick down cable. You get them confused and you can waste ppl's time and money. The kick down cable, if adjusted too tight, can create this problem, but in all reality, it is pretty hard to accidently do this.

05-17-2006, 09:51 PM	#7
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: TH 350 shifts a bit late...adjustable? no...I'm sorry if it sounded cockey... hell, you brought up a point no one else had mentioned.

05-17-2006, 09:59 PM	#8
jrb71c20 Registered User Join Date: Mar 2005 Location: Claremore, OK Posts: 486	Re: TH 350 shifts a bit late...adjustable? i replaced my modulator recently and it advised to adjust it by the bolt on the bracket holding it in...I put it in and loosened it to smooth out the shifting. The best part was, nothing spontaniously burst into flames...lol

05-18-2006, 06:01 AM	#9
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: TH 350 shifts a bit late...adjustable? that's a new one by me.

05-18-2006, 08:51 AM	#10
Gray Ghost Senior Member Join Date: Sep 2004 Location: Terrell, TX Posts: 1,967	Re: TH 350 shifts a bit late...adjustable? Thanks Longhorn Man....I'll try that this weekend. The TV cable is only on the 2004R & 700R4 4 speed autos....I've had one of each before and hated them with a passion. __________________ Kelly '05 GMC Sierra SLE Z71 Bone stock except for new bed rail caps.

05-18-2006, 09:04 AM	#11
Myself Registered User Join Date: Oct 2005 Location: Northern Arkansas Posts: 1,131	Re: TH 350 shifts a bit late...adjustable? Actually, the TV cable will be on anything with a lock-up torque converter. Including the 200c, 3sp, and some late model TH350.

05-18-2006, 09:10 AM	#12
Gray Ghost Senior Member Join Date: Sep 2004 Location: Terrell, TX Posts: 1,967	Re: TH 350 shifts a bit late...adjustable? Another thing I am not fond of....lock up TC's. __________________ Kelly '05 GMC Sierra SLE Z71 Bone stock except for new bed rail caps.

05-18-2006, 04:58 PM	#13
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: TH 350 shifts a bit late...adjustable? Myself, that is inacurate. There is a kick down cable on the TH200C and on the TH350C, not a throttle valve.

05-18-2006, 09:46 PM	#14
Canadian72GMC Registered User Join Date: Mar 2005 Location: north battleford, sk Posts: 30	Re: TH 350 shifts a bit late...adjustable? The kickdown cable is connected to the throttle pressure valve in the valve body, You are both correct.

05-18-2006, 11:06 PM	#15
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,713	Re: TH 350 shifts a bit late...adjustable? Here is a website that explains a lot about transmission shifting. http://yarchive.net/car/transmission.html __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.

05-19-2006, 12:21 PM	#17
DangerBoy Registered User Join Date: Nov 2005 Location: Springville, Ca Posts: 270	Re: TH 350 shifts a bit late...adjustable? On my TH-350 it will kickdown into 1st. Is that only on some models? __________________ 2002 S10 ZR2 for the dirt. 1968 C10 shorty for the street. She said the truck would be the end of us. I still have the truck!



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05-19-2006, 02:46 PM	#18
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: TH 350 shifts a bit late...adjustable? 350s will kick inot 1st. you may have me on the 200... I haven't even seen one since the 80's, and I was a kid back then.

05-19-2006, 03:32 PM	#19
Myself Registered User Join Date: Oct 2005 Location: Northern Arkansas Posts: 1,131	Re: TH 350 shifts a bit late...adjustable? Yeah the 200's were kinda junky , but they were ok for lighter, low horsepower applications.

05-19-2006, 03:58 PM	#20
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: TH 350 shifts a bit late...adjustable? yeah, it was funny when my buddy's chevette tore up a TH200. I couldn't believe it. That thing was so slow it was unreal.

05-19-2006, 04:11 PM	#21
Gray Ghost Senior Member Join Date: Sep 2004 Location: Terrell, TX Posts: 1,967	Re: TH 350 shifts a bit late...adjustable? The 'Ill-Fated '86 MCSS' had a 2004R....it was rebuilt when I had the motor out. I bought a 330hp HO 350 roller-cam crate motor [another mistake] and after we got it in and took it out for it's maiden voyage, the tranny tanked on the first shift into second gear. There went $1600. Before the MCSS I had an S-10 Blazer 4x4 with a 700R4 in it. That rebuild totaled over $600 [in '92]. While the 700's are much better trannys, to this day I destest GM's 4 sp autos from the lowly and vastly cheap 1980's cars and trucks. You could give me one, but I'd have it on ebay before you got back home. __________________ Kelly '05 GMC Sierra SLE Z71 Bone stock except for new bed rail caps.

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