1987 4x4 overdrive and 4wd not working - The 1947 - Present Chevrolet & GMC Truck Message Board Network

the walrus · 10-09-2008, 08:45 PM

My 1987 1/2 ton 4x4 TBI 305 TH700-R4 (completely stock) is not shifting into overdrive. The current extents of my troubleshooting have been limited to checking the fluid which is at the proper level. O.d. was engaging just fine a few hundered miles ago with no major events happening to the truck in the meantime. I'm pretty sure that it has a lock-up torque convertor which I can feel engaging in third gear after about 40mph under steady load but no o.d.
Any tips on where to start looking????

Also, on an unrelated note (I think) the front wheels are not being driven with 4wd engaged. Front hubs are manual warns and if I lock the hub, raise and spin the wheel the drive shaft turns with the hubs locked and idles with the hubs not locked, so I'm fairly confident that they are working correctly. 4x4 low ratio enages as it should, but only drives the rear wheels. Whats the first thing to look for???

thanks in advance.

84 400 · 10-10-2008, 12:03 AM

The 700r does use a lock up converter. I wish i could be more help then that but i am not an auto transmission person. which transfer case does your truck have? I had a jeep with a stretched transfer case chain and it would not engage the front axle in 4x4.

The 4x4 or drivetrain section of the forum could be a great help to you. They have answered everything I ever asked even if it was related to non chevy vehicles.

Also welcome from New Hampshire USA

Albatrossian · 10-10-2008, 07:17 AM

You say you can feel the converter locking but it won't go into 4th gear? Have you gone wheeling lately? Is the shifter mechanism working correctly? No binding?

smashingchuck · 10-10-2008, 10:14 AM

If the trans for some reason isn't getting power it will not lock up.

the walrus · 10-13-2008, 04:33 PM

Thanks for the advice, not sure what transfer case is have. I will follow 84 400's advice and cut and paste my question into another section.

Also thanks for the welcome, to introduce myself - a little about my automotive interests; my daily driver is a '87 4x4 305 TBI. Other vehicles I currently own include an '02 Mazda P5, a '73 Yamaha RD350 and a '70 Chevelle. The Chevelle is my first car and has doubled as a hobby for the past 12 years. Check out this link for look: http://www3.sympatico.ca/paul.brough/
My ftp server is currenty not working correctly, once it is I will update the site and post a pic of my daily driver (the above mentioned '87 4x4)

I will soon be proceeding with a budget minded refresh on the truck - some new interior components, fix the leaky gas tank, get the driveline back to fully functional and a new coat of paint, so I will likely hang around for a bit aksing quesions - stay tuned.

10-09-2008, 08:45 PM	#1
the walrus Registered User Join Date: Jun 2007 Location: ontario, canada Posts: 9	1987 4x4 overdrive and 4wd not working My 1987 1/2 ton 4x4 TBI 305 TH700-R4 (completely stock) is not shifting into overdrive. The current extents of my troubleshooting have been limited to checking the fluid which is at the proper level. O.d. was engaging just fine a few hundered miles ago with no major events happening to the truck in the meantime. I'm pretty sure that it has a lock-up torque convertor which I can feel engaging in third gear after about 40mph under steady load but no o.d. Any tips on where to start looking???? Also, on an unrelated note (I think) the front wheels are not being driven with 4wd engaged. Front hubs are manual warns and if I lock the hub, raise and spin the wheel the drive shaft turns with the hubs locked and idles with the hubs not locked, so I'm fairly confident that they are working correctly. 4x4 low ratio enages as it should, but only drives the rear wheels. Whats the first thing to look for??? thanks in advance.

10-10-2008, 12:03 AM	#2
84 400 Sb 400 club Join Date: Nov 2005 Location: NH / MA Posts: 2,741	Re: 1987 4x4 overdrive and 4wd not working The 700r does use a lock up converter. I wish i could be more help then that but i am not an auto transmission person. which transfer case does your truck have? I had a jeep with a stretched transfer case chain and it would not engage the front axle in 4x4. The 4x4 or drivetrain section of the forum could be a great help to you. They have answered everything I ever asked even if it was related to non chevy vehicles. Also welcome from New Hampshire USA __________________ 1984 chevy c10, built 400sb,.(SOLD) 77 K10 Project / daily driver "The Grinch" http://67-72chevytrucks.com/vboard/s...d.php?t=318363 1956 Willys Wagon (327 chevy) Project (Now Buick 225) 1980 Corvette L-48 4 speed 1992 Mustang GT built 5.0 5 speed 1985 C10 LWB Sold 1982 K10 SWB plow truck Parted out 1986 D30 M1028 fire brush truck Parted out Last edited by 84 400; 10-10-2008 at 12:04 AM.

10-10-2008, 07:17 AM	#3
Albatrossian Georgia Boy Join Date: Jun 2008 Location: Douglas, Georgia Posts: 370	Re: 1987 4x4 overdrive and 4wd not working You say you can feel the converter locking but it won't go into 4th gear? Have you gone wheeling lately? Is the shifter mechanism working correctly? No binding?

10-10-2008, 10:14 AM	#4
smashingchuck It'd be alot cooler if you did Join Date: May 2003 Location: Three Rivers, MI Posts: 2,345	Re: 1987 4x4 overdrive and 4wd not working If the trans for some reason isn't getting power it will not lock up. __________________ 78 Build Thread 4Runner Build

10-13-2008, 04:33 PM	#5
the walrus Registered User Join Date: Jun 2007 Location: ontario, canada Posts: 9	Re: 1987 4x4 overdrive and 4wd not working Thanks for the advice, not sure what transfer case is have. I will follow 84 400's advice and cut and paste my question into another section. Also thanks for the welcome, to introduce myself - a little about my automotive interests; my daily driver is a '87 4x4 305 TBI. Other vehicles I currently own include an '02 Mazda P5, a '73 Yamaha RD350 and a '70 Chevelle. The Chevelle is my first car and has doubled as a hobby for the past 12 years. Check out this link for look: http://www3.sympatico.ca/paul.brough/ My ftp server is currenty not working correctly, once it is I will update the site and post a pic of my daily driver (the above mentioned '87 4x4) I will soon be proceeding with a budget minded refresh on the truck - some new interior components, fix the leaky gas tank, get the driveline back to fully functional and a new coat of paint, so I will likely hang around for a bit aksing quesions - stay tuned. Last edited by the walrus; 10-13-2008 at 04:34 PM.



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