CK5
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700R4 help please
- Thread starter F-ingrob
- Start date
What, you don't own any tarps or a boat?
I do have tarps, and I'll admit that the '84 is nearly on par with a boat anchor at this point.
But I'd like the '83 to last for a long, long time.
What are the downsides to the 27-spline input shafts?
Its a small diameter shaft, but the rest of the trans also has some pretty weak stuff compared to the later units. Back in the early 80's I used these 27 spline units behind some pretty healthy engines, including big blocks because it was all we had to work with. I shy away from them today because the later units are so much better but don't be afraid to run what you have for as long as it will serve you, I have seen some early 700's go 300K miles if not abused.
The 700R4 in my '85 K10 Suburban is ailing,it doesn't always shift into OD and sometimes has no reverse after it was driven some miles,like 10-15,according to the previous owner...so it'll likely need a rebuild,or be swapped out..(has worked fine in my driveway since I got it,but its never been put on the road yet since buying it long ago).
My question is if it is the original '85 tranny,is it worth having rebuilt,or would it be more sensible to get an '87 up version from a salvage yard (whether its "good" or also needs rebuilding ?)...sounds like if the '85 only has the bigger splined input,but its still lacking the auxillary valve body and other upgrades,its not as desireable...(and I do have some tarps that need to be held down..
)..
What sucks is a friend of mine has scrapped several 700R4's from GM trucks in the '87-91 range when he replaced them with salvage yard ones--I should have snagged them and saved them for future rebuilds..
One of them he swore had nothing wrong with it--the truck's transfer case was in neutral when it arrived on a ramp truck--after putting it back in gear he drove it around several miles and said it shifted and sounded fine..the woman driving the truck said it drove fine to the store--then would not move when she went to leave,and made a loud grinding noise..my friend suspects she had her purse on the console and may have pulled the t-case into neutral when she grabbed the purse..
He told the husband the transmission seemed fine--he said "replace it anyway,its got 180,000 miles anyway--if I dont,she'll be scared to drive it again.."..two days later the original trans was put in the trunk of a junk car,and taken to the scrapyard..
My question is if it is the original '85 tranny,is it worth having rebuilt,or would it be more sensible to get an '87 up version from a salvage yard (whether its "good" or also needs rebuilding ?)...sounds like if the '85 only has the bigger splined input,but its still lacking the auxillary valve body and other upgrades,its not as desireable...(and I do have some tarps that need to be held down..
)..What sucks is a friend of mine has scrapped several 700R4's from GM trucks in the '87-91 range when he replaced them with salvage yard ones--I should have snagged them and saved them for future rebuilds..
One of them he swore had nothing wrong with it--the truck's transfer case was in neutral when it arrived on a ramp truck--after putting it back in gear he drove it around several miles and said it shifted and sounded fine..the woman driving the truck said it drove fine to the store--then would not move when she went to leave,and made a loud grinding noise..my friend suspects she had her purse on the console and may have pulled the t-case into neutral when she grabbed the purse..
He told the husband the transmission seemed fine--he said "replace it anyway,its got 180,000 miles anyway--if I dont,she'll be scared to drive it again.."..two days later the original trans was put in the trunk of a junk car,and taken to the scrapyard..
If you are just putting around the 85 trans will be OK, you can actually put most of the improved design parts, such as the input and low sprags into the earlier trans, it makes a good upgrade.
