Hey guys, not a Chevelle issue, but with my '86 K5 Blazer 4x4 (full size). The truck is my daily driver so I gotta get it fixed quick.

Anyway here's so background. I bought the truck recently, the tranny was rebuilt/beefed/updated/shift kit installed. According to the shop receipt I have it was done 6000 miles ago, but over a year has past so the warranty is expired. Plus the tranny shop that did the work is 600 miles away.

The truck and tranny have been working flawlessly since I bought it. Here's the problem. Today I was driving to work and after 5 mins of driving I start hearing a grinding noise over my radio. So, I start to make a turn onto a side street so I could pull over. As I slowed down to make the turn the tranny suddenly shifts down and when I complete the turn its like the tranny is no longer there when I went to apply the gas. I make a complete stop and try every gear, including reverse......nothing. Then when trying to place it in PARK it just grinds when trying to move the shifter. If the motor is off I can place the tranny in PARK, but the truck can still be pushed forward as if in neutral.

I checked the transfer case, it isn't the problem.

I am totally stumped. I am not a tranny guy by any means, so I need your help.


Any and all suggestions are welcomed and thanked in advance.

The park situation sounds like the internal shift lever isn't connected to the shifter. The lever mechanically locks the pawl that gives you "park".

I don't know what caused your initial problem though. I have had a transmission line spring a tiny leak which lowered the fluid level enough to make the transmission stop engaging.

i had a torque converter give up on me driving down the road one day. there i set.

Thanks for the suggestions guys.

There is no leaks of any kind, so line pressure wouldn't be an issue.

Plus no "PARK" and no gears at the same time is prob a larger issue than just the interial parking rod.

The converter wouldn't be the blame either because it has nothing to do with "park". Believe me I wish it was the converter.


Anyone else have any input? Thanks again.

Shift linkage inside the trans broke as cjlandry suggested, drop pan and fix it...

I`m gonna take a SWAG sounds like the trans is turning cause of the grinding when you try to put it in park with the engine running. If that`s the case it`s something between the trans & the transfer case.

Jim

I just had the 700 in 3/4 ton rebuilt. My trans guy showed me what could be wrong which was a box full of parts and later showed me what was wrong, a box full of part. Good luck. graemlins/sad.gif

Tranfer case, chain or drive gears maybe?
Did you try low range?

Originally posted by jakeshoe:
Shift linkage inside the trans broke as cjlandry suggested, drop pan and fix it... I guess I am alittle fuzzy on how the interial linkage would cause me lose all gears and PARK while it is moving and in gear. If I just jumped into and started the truck after sitting overnight and had no gears or park I could see alittle easier how it could be the interial linkage issue.

I plan on dropping the pan either tonight or tomorrow morning. I am really hoping it is something that easy.

Thanks guys, keep'em coming!!

Oops, Double Post

Actually after rereading your original post and thinking about it...
I think 77 cruiser is right.

You've either broken the trans output shaft (fairyy unlikely) or hurt the transfer case, OR if you are lucky the transfer case linkage.

here's the reasoning:
Have you ever had a car on a lift or stands and been spinning the tires up, then hit the brakes, go to put it in park prematurely and heard the park pawl growl against the gear?

That's is what you are experiencing now, the output shaft is spinning and you are trying to go to park.
SO that tells me that the transmission IS driving the output shaft (good thing) and the linkage is trying to work from the column to the trans internally.
So if the trans is working then something else is amiss.
A broken chain or input in the T-case would cause the symptoms you are experiencing as well as if the T-case somehow got popped into neutral, by the shifter or by the linage getting out of whack.

Recheck you t-case...

Now comes the weird part......


I just went outside after getting home from work to check things out.

Well.....I wanted to hear the grinding noise again so I fired it up and put it in reverse thinking it wouldn't do anything. Much to my suprise it enguaged reverse and everyother gear too. Plus the grind I got when putting in "PARK" is gone too.

I want to be excited, but I am still worried. I didn't drive it to see if it will shift or not because I am worried it will leave me pushing it again. I checked the fluid level on the stick is nice and pink and doesn't smell burnt at all.

If you put the transfer case in neutral ,Park will not work. Many people killed by this happening while kids left unattended playing in the 4x4 with no e-brake set!

Originally posted by jakeshoe:

So if the trans is working then something else is amiss.
A broken chain or input in the T-case would cause the symptoms you are experiencing as well as if the T-case somehow got popped into neutral, by the shifter or by the linage getting out of whack.

Recheck you t-case... Update:

I am 99% sure that the transfer case is to blame. It is a New Process 208 C transfer case. It has an aluminum case, part time, chain driven.

Anyway, after getting the tranny/tranfer case to operating temp (with the motor just sitting in my driveway at idle) it starting happening again when I played with the tranny/transfer case.

While playing with the transfer case and trying to shift into "N" I get alot of grinding, I can't even make it into "4L". Then if I put it back into "2H" and try to put the tranny into "P" I get the grinding again unless I turn the motor off first.

This Blazer is my first 4x4, so this whole thing is new to me. I always thought that the transfer case was "direct drive", but I guess it turns out there is a pump and planetary gear set in it too. I am guessing that it is either of the two that has gone south. To the best of my knowing, the transfer case has never been rebuilt.

So why would it work when its cold and not when its at operating temp? I am planning on rebuilding the transfer case now, but what do you guys think went bad?

The transfer case is direct drive to the rear wheels when you're in 2wd-hi or 4wd-hi. The planetary gearset is for the low range. Something inside it is worn out which is causing it to jump out of gear. There are a number of bearings and gear selection sliders and then the shift forks and detents and so there are a number of things that can go wrong in it. A bearings failing seems to be a likely cause.

It won't be the chain because that would just remove the drive from the front wheels.

Peter

Originally posted by Peter F.:
The transfer case is direct drive to the rear wheels when you're in 2wd-hi or 4wd-hi. The planetary gearset is for the low range. Something inside it is worn out which is causing it to jump out of gear. There are a number of bearings and gear selection sliders and then the shift forks and detents and so there are a number of things that can go wrong in it. A bearings failing seems to be a likely cause.

It won't be the chain because that would just remove the drive from the front wheels.

Peter A local 4x4 guru thinks the selector fork or something like that broke or came loose.

I plan on getting it checked out next week sometime.

I've definitely learned something about transfer cases by reading this thread. I knew absolutely nothing about 4x4's, now I know a tiny little bit.

If not for the transfer case, the "park" situation would have been completely illogical.

Originally posted by cjlandry:
I've definitely learned something about transfer cases by reading this thread. I knew absolutely nothing about 4x4's, now I know a tiny little bit.

If not for the transfer case, the "park" situation would have been completely illogical. I guess the saying true that, "you learn something everyday".

Well guys, I found a decent shop that a friend recommended. It was a 45 min drive to get to him, but I think it was worth it.

It turns out that that there were more than just one problem. The pads on the fork weren't the problem....because the fork was eaten up. Not only that but the front input shaft carrier bearing assembley was toast too. He thinks that my MPG might improve with that being fixed since with the extra resistance was kinda working against itself.

The guy is totally cool though. He originally quoted me $150 part AND labor to yank the T-Case and replace the pads. He got the shifter fork from the dealer ($80) and the whole front bearing assembley from a donor NP208C that cracked its case. He is only charging $40 for it. He is not charging me any extra labor for the extra work. So I am only looking at $270 and I am back in business.

It gets better. Because the dealer was slow in delivering the fork, he didn't get it finished today. So, he is coming in tommorrow to finish it (Saturday) so I can have it for work on Sunday.

To say the least I am VERY impressed with this man. I am into drag racing and I am always looking for a decent and trustworthy builder for my Th400's....I think I found him.

Automatic Transmission Specialists
Visalia, Ca.
(559) 732-3320