O.D. tranny problems - The 1947 - Present Chevrolet & GMC Truck Message Board Network

gearhead dave · 10-25-2001, 08:06 PM

i have a 1985 S-10 Blazer with the 2.8 engine and O.D. trans.

the problem is the trans goes in and out of overdrive at highway speeds, and i don't know squat about the types of trans. Any help that will get me looking in the right direction will be greatly appreciated.

thanks'
Dave

------------------
1976 Crew Cab Dually (under construction)
1972 Suburban
1955 Pro Street Chevy
1985 S-10 Blazer (daily driver)
V W Sandrail
Located in Horn Lake, MS that's just 4 miles south of Memphis TN

www.classictruckshop.com/clubs/earlyburbs/members/gallery2/223/display.htm

Former engine builder for Racing Head Service
Performance Engines in Memphis TN. over 1,600 plus engines built by little ole me!!

GOD BLESS THE BRAVEST OF THE BRAVE...THE NEW YORK CITY FIRE FIGHTERS!!

Longhorn Man · 10-26-2001, 12:12 AM

well, first you have to determine if it is going from 4th to 3rd, of if the converter is just locking up/unlocking. The 2 can be simaler.
On the freeway, place the truck in 3rd.(or drive). if the RPM's jump up higher than what you are used to hearin, it's the verter, if it is about what you are used to hearin, it is the tranny.
The best thing you can do, is drain the fluid and chainge the filter. Then, keep it in 3rd or D untill you are doin more than 50 MPH. Also, never tow in OD (4th).
Either one, the verter, or the tranny, will make you wanna junk the truck when you get an estimate. Esp if it is a 4X4.

gearhead dave · 10-26-2001, 06:08 PM

longhornmail,
according to your dianogsis, it is the 'verter, how much do these things cost to replace?

thanks
dave

------------------
1976 Crew Cab Dually (under construction)
1972 Suburban
1955 Pro Street Chevy
1985 S-10 Blazer (daily driver)
V W Sandrail
Located in Horn Lake, MS that's just 4 miles south of Memphis TN

www.classictruckshop.com/clubs/earlyburbs/members/gallery2/223/display.htm

Former engine builder for Racing Head Service
Performance Engines in Memphis TN. over 1,600 plus engines built by little ole me!!

GOD BLESS THE BRAVEST OF THE BRAVE...THE NEW YORK CITY FIRE FIGHTERS!!

Longhorn Man · 10-26-2001, 07:16 PM

Honestly, I am not sure. I do know lock up verters are no where near cheap. I would guestimate 2 to 3 hundred. Plus labor if you are unable.
Some thing I would like to add also, please have the diagnosis confirmed by a pro. I am not a pro, and I just shot out some guidelines to help eliminate things. However, go to a good shop, and even a couple differant shops. I have found, that more tranny shops are run by crooks than any other type of auto shop. (just my opservation here)

**Boog** · 11-11-2001, 08:34 AM

Hey guys. I recently had the same thing happening to my 85 K5 blazer. Everything ran out ok but it kept jumping in and out of what I thought was overdrive. My handy test light narrowed it down to the switch on the brake pedal. There are two sets of wires on mine. It not only turns the brake lights on but breaks the circuit to the converter when you apply the brakes. The switch needs to be adjusted right up next to the brake pedal to operate right. If not, any slack there will cause the converter to jump in and out. Fixed mine ok. Boog

Longhorn Man · 11-12-2001, 09:48 PM

Dave, what's the word?
Boog has a good point too, I didn't think of that...

------------------
The hot rod;
a'69 G.M.C. Short/Fleet. 350 W/a heluva cam and nice stance. Still a beater though. Trying to clean up the left over damage from the Dope-Smokin-Old-Man...a real bummer. See it at http://geocities.com/andys_69_gmc/

I've been dubbed the Longhorn Freak/Fanatic/Expert, I just hope I can live up to it. Check out my Longhorn site at http://geocities.com/MotorCity/Flats/8752/
IM me on Yahoo pager...cockroach93.
hey, stop laughing!!!

gearhead dave · 11-12-2001, 09:57 PM

well, i got rearended on the freeway in Memphis right after i posted this, but the body work is now taking place.

tail gate, rear bumper, rear valance panel, front bumper and valance panel, and the seat frame got bent too, from me flying into the back seat when i got hit from behind.

I'll let you guys know what's up when i get the truck back on the road, hopefully after the Thanksgiving weedend

thanks
Dave

------------------
1976 Crew Cab Dually (under construction)
1972 Suburban
1955 Pro Street Chevy
1985 S-10 Blazer (daily driver)
V W Sandrail
Located in Horn Lake, MS that's just 4 miles south of Memphis TN
www.classictruckshop.com/clubs/earlyburbs/members/gallery2/223/display.htm

Former engine builder for Racing Head Service
Performance Engines in Memphis TN. over 1,600 plus engines built by little ole me!!

GOD BLESS THE BRAVEST OF THE BRAVE...THE NEW YORK CITY FIRE FIGHTERS!!

[This message has been edited by gearhead dave (edited 11-12-2001).]

Longhorn Man · 11-13-2001, 11:28 PM

OUCH. When you get it back, tell them that your tranny is messin up now too.

------------------
The hot rod;
a'69 G.M.C. Short/Fleet. 350 W/a heluva cam and nice stance. Still a beater though. Trying to clean up the left over damage from the Dope-Smokin-Old-Man...a real bummer. See it at http://geocities.com/andys_69_gmc/

I've been dubbed the Longhorn Freak/Fanatic/Expert, I just hope I can live up to it. Check out my Longhorn site at http://geocities.com/MotorCity/Flats/8752/
IM me on Yahoo pager...cockroach93.
hey, stop laughing!!!

gearhead dave · 01-05-2002, 11:48 PM

well, here it is the new year and the blazer is still not on the road, so far i have relaced the tail gate, passenger side fender and door, rear bumper and valance panel, front valance panel and am still looking for a good front bumper. Oh yeah, i lowered it 3" in the rear and 4" in the front and put a set of 16" IROC wheels on it. I found out that the rear seal is bad on the tranny, got the drive shaft out and am going to replace that and the u-joints tomorrow. Just thought that i would give a quick update.

Future plans.....putting the motor from the 'burb in it.

later
dave

------------------
1976 Crew Cab Dually (under construction)
1972 Suburban
1955 Pro Street Chevy
1985 S-10 Blazer (daily driver)
V W Sandrail
Located in Horn Lake, MS that's just 4 miles south of Memphis TN

www.classictruckshop.com/clubs/earlyburbs/members/gallery2/223/display.htm

Former engine builder for Racing Head Service
Performance Engines in Memphis TN. over 1,600 plus engines built by little ole me!!

GOD BLESS THE BRAVEST OF THE BRAVE...THE NEW YORK CITY FIRE FIGHTERS!!

10-25-2001, 08:06 PM	#1
gearhead dave Registered User Join Date: Jul 2000 Location: horn lake,ms Posts: 388	O.D. tranny problems i have a 1985 S-10 Blazer with the 2.8 engine and O.D. trans. the problem is the trans goes in and out of overdrive at highway speeds, and i don't know squat about the types of trans. Any help that will get me looking in the right direction will be greatly appreciated. thanks' Dave ------------------ 1976 Crew Cab Dually (under construction) 1972 Suburban 1955 Pro Street Chevy 1985 S-10 Blazer (daily driver) V W Sandrail Located in Horn Lake, MS that's just 4 miles south of Memphis TN www.classictruckshop.com/clubs/earlyburbs/members/gallery2/223/display.htm Former engine builder for Racing Head Service Performance Engines in Memphis TN. over 1,600 plus engines built by little ole me!! GOD BLESS THE BRAVEST OF THE BRAVE...THE NEW YORK CITY FIRE FIGHTERS!! __________________ 1976 Crew Cab Dually (under construction) 1972 Suburban 1955 Pro Street Chevy 1985 S-10 Blazer (daily driver) V W Sandrail Located in Horn Lake, MS that's just 4 miles south of Memphis TN www.classictruckshop.com/clubs/earlyburbs/members/gallery2/223/display.htm Former engine builder for Racing Head Service Performance Engines in Memphis TN. over 1,600 plus engines built by little ole me!! GOD BLESS THE BRAVEST OF THE BRAVE...THE NEW YORK CITY FIRE FIGHTERS!!

10-26-2001, 06:08 PM	#3
gearhead dave Registered User Join Date: Jul 2000 Location: horn lake,ms Posts: 388	longhornmail, according to your dianogsis, it is the 'verter, how much do these things cost to replace? thanks dave ------------------ 1976 Crew Cab Dually (under construction) 1972 Suburban 1955 Pro Street Chevy 1985 S-10 Blazer (daily driver) V W Sandrail Located in Horn Lake, MS that's just 4 miles south of Memphis TN www.classictruckshop.com/clubs/earlyburbs/members/gallery2/223/display.htm Former engine builder for Racing Head Service Performance Engines in Memphis TN. over 1,600 plus engines built by little ole me!! GOD BLESS THE BRAVEST OF THE BRAVE...THE NEW YORK CITY FIRE FIGHTERS!! __________________ 1976 Crew Cab Dually (under construction) 1972 Suburban 1955 Pro Street Chevy 1985 S-10 Blazer (daily driver) V W Sandrail Located in Horn Lake, MS that's just 4 miles south of Memphis TN www.classictruckshop.com/clubs/earlyburbs/members/gallery2/223/display.htm Former engine builder for Racing Head Service Performance Engines in Memphis TN. over 1,600 plus engines built by little ole me!! GOD BLESS THE BRAVEST OF THE BRAVE...THE NEW YORK CITY FIRE FIGHTERS!!

11-11-2001, 08:34 AM	#5
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 13,039	Hey guys. I recently had the same thing happening to my 85 K5 blazer. Everything ran out ok but it kept jumping in and out of what I thought was overdrive. My handy test light narrowed it down to the switch on the brake pedal. There are two sets of wires on mine. It not only turns the brake lights on but breaks the circuit to the converter when you apply the brakes. The switch needs to be adjusted right up next to the brake pedal to operate right. If not, any slack there will cause the converter to jump in and out. Fixed mine ok. Boog __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross

11-12-2001, 09:57 PM	#7
gearhead dave Registered User Join Date: Jul 2000 Location: horn lake,ms Posts: 388	well, i got rearended on the freeway in Memphis right after i posted this, but the body work is now taking place. tail gate, rear bumper, rear valance panel, front bumper and valance panel, and the seat frame got bent too, from me flying into the back seat when i got hit from behind. I'll let you guys know what's up when i get the truck back on the road, hopefully after the Thanksgiving weedend thanks Dave ------------------ 1976 Crew Cab Dually (under construction) 1972 Suburban 1955 Pro Street Chevy 1985 S-10 Blazer (daily driver) V W Sandrail Located in Horn Lake, MS that's just 4 miles south of Memphis TN www.classictruckshop.com/clubs/earlyburbs/members/gallery2/223/display.htm Former engine builder for Racing Head Service Performance Engines in Memphis TN. over 1,600 plus engines built by little ole me!! GOD BLESS THE BRAVEST OF THE BRAVE...THE NEW YORK CITY FIRE FIGHTERS!! [This message has been edited by gearhead dave (edited 11-12-2001).] __________________ 1976 Crew Cab Dually (under construction) 1972 Suburban 1955 Pro Street Chevy 1985 S-10 Blazer (daily driver) V W Sandrail Located in Horn Lake, MS that's just 4 miles south of Memphis TN www.classictruckshop.com/clubs/earlyburbs/members/gallery2/223/display.htm Former engine builder for Racing Head Service Performance Engines in Memphis TN. over 1,600 plus engines built by little ole me!! GOD BLESS THE BRAVEST OF THE BRAVE...THE NEW YORK CITY FIRE FIGHTERS!!

01-05-2002, 11:48 PM	#9
gearhead dave Registered User Join Date: Jul 2000 Location: horn lake,ms Posts: 388	well, here it is the new year and the blazer is still not on the road, so far i have relaced the tail gate, passenger side fender and door, rear bumper and valance panel, front valance panel and am still looking for a good front bumper. Oh yeah, i lowered it 3" in the rear and 4" in the front and put a set of 16" IROC wheels on it. I found out that the rear seal is bad on the tranny, got the drive shaft out and am going to replace that and the u-joints tomorrow. Just thought that i would give a quick update. Future plans.....putting the motor from the 'burb in it. later dave ------------------ 1976 Crew Cab Dually (under construction) 1972 Suburban 1955 Pro Street Chevy 1985 S-10 Blazer (daily driver) V W Sandrail Located in Horn Lake, MS that's just 4 miles south of Memphis TN www.classictruckshop.com/clubs/earlyburbs/members/gallery2/223/display.htm Former engine builder for Racing Head Service Performance Engines in Memphis TN. over 1,600 plus engines built by little ole me!! GOD BLESS THE BRAVEST OF THE BRAVE...THE NEW YORK CITY FIRE FIGHTERS!! __________________ 1976 Crew Cab Dually (under construction) 1972 Suburban 1955 Pro Street Chevy 1985 S-10 Blazer (daily driver) V W Sandrail Located in Horn Lake, MS that's just 4 miles south of Memphis TN www.classictruckshop.com/clubs/earlyburbs/members/gallery2/223/display.htm Former engine builder for Racing Head Service Performance Engines in Memphis TN. over 1,600 plus engines built by little ole me!! GOD BLESS THE BRAVEST OF THE BRAVE...THE NEW YORK CITY FIRE FIGHTERS!!

10-26-2001, 12:12 AM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	well, first you have to determine if it is going from 4th to 3rd, of if the converter is just locking up/unlocking. The 2 can be simaler. On the freeway, place the truck in 3rd.(or drive). if the RPM's jump up higher than what you are used to hearin, it's the verter, if it is about what you are used to hearin, it is the tranny. The best thing you can do, is drain the fluid and chainge the filter. Then, keep it in 3rd or D untill you are doin more than 50 MPH. Also, never tow in OD (4th). Either one, the verter, or the tranny, will make you wanna junk the truck when you get an estimate. Esp if it is a 4X4.

10-26-2001, 07:16 PM	#4
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Honestly, I am not sure. I do know lock up verters are no where near cheap. I would guestimate 2 to 3 hundred. Plus labor if you are unable. Some thing I would like to add also, please have the diagnosis confirmed by a pro. I am not a pro, and I just shot out some guidelines to help eliminate things. However, go to a good shop, and even a couple differant shops. I have found, that more tranny shops are run by crooks than any other type of auto shop. (just my opservation here)

11-12-2001, 09:48 PM	#6
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Dave, what's the word? Boog has a good point too, I didn't think of that... ------------------ The hot rod; a'69 G.M.C. Short/Fleet. 350 W/a heluva cam and nice stance. Still a beater though. Trying to clean up the left over damage from the Dope-Smokin-Old-Man...a real bummer. See it at http://geocities.com/andys_69_gmc/ I've been dubbed the Longhorn Freak/Fanatic/Expert, I just hope I can live up to it. Check out my Longhorn site at http://geocities.com/MotorCity/Flats/8752/ IM me on Yahoo pager...cockroach93. hey, stop laughing!!!

11-13-2001, 11:28 PM	#8
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	OUCH. When you get it back, tell them that your tranny is messin up now too. ------------------ The hot rod; a'69 G.M.C. Short/Fleet. 350 W/a heluva cam and nice stance. Still a beater though. Trying to clean up the left over damage from the Dope-Smokin-Old-Man...a real bummer. See it at http://geocities.com/andys_69_gmc/ I've been dubbed the Longhorn Freak/Fanatic/Expert, I just hope I can live up to it. Check out my Longhorn site at http://geocities.com/MotorCity/Flats/8752/ IM me on Yahoo pager...cockroach93. hey, stop laughing!!!



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