1997 Suburban 4x4, 4l60e no reverse, imagine that. - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Transmission - Rearend
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 10-09-2009, 11:14 PM
Registered User
 
Join Date: Oct 2009
Location: Indiana
Posts: 28
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
1997 Suburban 4x4, 4l60e no reverse, imagine that.

OK guys, I know you all have beat the "no reverse" issue to death, but please don;t beat me. I've searched alot of the posts dealing with this problem, but havn't found the exact symptoms mine has. Myabe someone can enlighten me.
97 Suburban 4x4. Rebuilt tranny has 16,000 miles on it. Bought it through an internet advertising "builder". Came with a 1 yr unlimited milage warranty. It's been a yr and a half. Anyway, on startup after sitting overnight, it would take 3 or 4 seconds for it to go into reverse. Then it progressed to not going into reverse, or I'd have to jiggle the shifter and then it MIGHT go into reverse. Now, it won't do even that. Drive is on a slight grade, so I'll roll out of driveway, in reverse, but not actually engaged in reverse, drive around for awhile, and it MIGHT shift into reverse after its up to operating temp. Sometimes, after it does go into reverse, it might shudder as I gently backup, but sometimes, it'll back up normally, even to the point that I can hold on the brake and gas it easily, and I can tell that it is FIRMLY in reverse with no slipping to speak of. I talked to the rebuilder and he's thinking cracked low/reverse cluth piston....due to it behaving more normal after it's up to temp. The fact that I can jiggle the shifter and that sometimes helps makes me wonder if it could be in the boost valve in the valve body.
All forward gears seem to be just fine....I can watch the rpm drop at each shift. Not sure of the engine braking in manual 1st gear. I can take it up to about 20 mph in manual 1 and let off and it doesn;t "engine brake" until it has gradually slowed to about 15 mph...then it engine brakes noticably. Oh, I have not put a pressure gauge on it yet, so I don;t know what line pressures are. Any ideas or suggestions?
Thanks for the patience with the newbie here.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 10-10-2009, 07:21 AM
SSedan64's Avatar
Registered User
 
Last photo:
Join Date: Dec 2007
Location: Macon, GA.
Age: 50
Posts: 6,016
Wiki Edits: 0

Thanks: 0
Thanked 46 Times in 46 Posts
Another possibility is the gear position sensor may be bad. Wouldn't have anything to do with the engine braking symptom tho'.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 10-10-2009, 07:30 AM
Crosley's Avatar
Hotrodders.com Moderator
 
Last wiki edit: T-350 rebuild tech
Last journal entry: Bar under the dash
Last photo:
Join Date: Nov 2002
Location: ... USA
Posts: 7,980
Wiki Edits: 1659

Thanks: 257
Thanked 85 Times in 82 Posts
Quote:
Originally Posted by t00lmanii
OK guys, I know you all have beat the "no reverse" issue to death, but please don;t beat me. I've searched alot of the posts dealing with this problem, but havn't found the exact symptoms mine has. Myabe someone can enlighten me.
97 Suburban 4x4. Rebuilt tranny has 16,000 miles on it. Bought it through an internet advertising "builder". Came with a 1 yr unlimited milage warranty. It's been a yr and a half. Anyway, on startup after sitting overnight, it would take 3 or 4 seconds for it to go into reverse. Then it progressed to not going into reverse, or I'd have to jiggle the shifter and then it MIGHT go into reverse. Now, it won't do even that. Drive is on a slight grade, so I'll roll out of driveway, in reverse, but not actually engaged in reverse, drive around for awhile, and it MIGHT shift into reverse after its up to operating temp. Sometimes, after it does go into reverse, it might shudder as I gently backup, but sometimes, it'll back up normally, even to the point that I can hold on the brake and gas it easily, and I can tell that it is FIRMLY in reverse with no slipping to speak of. I talked to the rebuilder and he's thinking cracked low/reverse cluth piston....due to it behaving more normal after it's up to temp. The fact that I can jiggle the shifter and that sometimes helps makes me wonder if it could be in the boost valve in the valve body.
All forward gears seem to be just fine....I can watch the rpm drop at each shift. Not sure of the engine braking in manual 1st gear. I can take it up to about 20 mph in manual 1 and let off and it doesn;t "engine brake" until it has gradually slowed to about 15 mph...then it engine brakes noticably. Oh, I have not put a pressure gauge on it yet, so I don;t know what line pressures are. Any ideas or suggestions?
Thanks for the patience with the newbie here.

Why would you think it might be the boost valve if you jiggle the shifter? I would look at the shifter adjustment.

If the forward gears are fine , the boost valve must be working. Or darn close to correct specs I would guess

There must be a problem in the reverse gear circuit. The low-reverse clutches and the reverse input clutch pack make up reverse.

I have seen quite a few cracked pistons inside transmittins, never seen a low-reverse piston cracked yet. I have seen very hard seals on the low-reverse pistons because budget builders do not remove the low-reverse piston since it can be time consuming.

ALso ; on the reverse input srum piston , I always down size the OEM bleed hole to speed up the application of the apply.

A pressure check of main line pressure will help here... as you place the trans into reverse , watch the gauge. If it drops real low for a few seconds and does not recover quickly(or at all) that will indicate a leak and possible weak pump.

These pumps in the 4L60 trans must be setup to a close tolerance of .0015 - .002

__________________
Some people are like Slinkies... Not really good for anything, but they still bring a smile to your face when you push them down a flight of stairs.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 10-10-2009, 08:35 AM
Registered User
 
Join Date: Oct 2009
Location: Indiana
Posts: 28
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
"Why would you think it might be the boost valve if you jiggle the shifter? I would look at the shifter adjustment."
Crosley......I don't know, I guess that shows my ignorance of this transmission and how it works. I've been searching for all the info I can, in a short period of time and I don't really understand how it all works. I was thinking jiggling the shifter was moving the "valve" that directs fluid to the reverse circit, the mechanically linked valve.....I'll take the fifth to protect myself.
I'll try to get a gauge hooked up today and see what that shows.
Thanks for the advice guys. Oh, and Crosley, I was especially hoping that you would see this post and reply. From my lurking here for awhile I've noticed that you are the transmission guru to listen to.
SSedan64, are you saying that my description of engine braking taking place does indicate a "sympton"?,,,,,,,the very gradual slowing down until about 15 mph, then a very noticable braking taking place.
Thanks
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 10-10-2009, 09:28 AM
SSedan64's Avatar
Registered User
 
Last photo:
Join Date: Dec 2007
Location: Macon, GA.
Age: 50
Posts: 6,016
Wiki Edits: 0

Thanks: 0
Thanked 46 Times in 46 Posts
I was saying the engine braking symptom you described wouldn't be related to the gear position sensor.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 10-10-2009, 06:03 PM
Crosley's Avatar
Hotrodders.com Moderator
 
Last wiki edit: T-350 rebuild tech
Last journal entry: Bar under the dash
Last photo:
Join Date: Nov 2002
Location: ... USA
Posts: 7,980
Wiki Edits: 1659

Thanks: 257
Thanked 85 Times in 82 Posts
toolmanii... i should explain my question on the : "jiggle the shifter and boost valve connection" you mention.

It was only curiosity on my part.... I find it interesting on what non-auto mechanic folks connect together on transmissions.

I've seen folks question the reverse section of the torque converter. They have the thought that the modern converter reverses the power input to the transmission for the vehicle to back up.

If the shifter linkage on the exterior or interior is goof'd up , that can affect engagement of the trans into gear. I suspect on a reverse problem since you indicate the forward gears are fine.
__________________
Some people are like Slinkies... Not really good for anything, but they still bring a smile to your face when you push them down a flight of stairs.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 10-10-2009, 08:36 PM
Registered User
 
Join Date: Oct 2009
Location: Indiana
Posts: 28
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
well, I didn't get a gauge hooked up today. There wasn't any shops around that had the fittings I needed. I'll wait till Mon to get what I need at work. I need an 1/8 to #6 to go in the pressure port, and a 1/4 pipe to 1/4 pipe coupler to fit the gauge to a hose I'll make up.
Crosley, the "jiggle the shifter" comment, here's what I was thinking. At my shop, I park on a slight grade, front of vehicle is elevated. I have a habit of not using the parking brake. Often, when I go to leave, start the truck, and I have a HARD time moving the shifter out of Park, I thought maybe I bent/straightened the internal shifter linkage that moves the valve that directs fluid to the reverse circuit. Is that something that could be possible, or am I out to lunch?
Anyway, this thing is weird. Sometimes I can shift the shifter in and out of reverse...from neutral to reverse, or Park to reverse, and it MIGHT go into gear (reverse). When it does go into reverse, it might be FIRMLY in gear, or it might slip, or it might be in gear just enough to show a very slight drop in RPM's, but not engaged in gear enough to allow the vehicle to back up at all, even on flat ground.
I guess all I can do is wait till I get the gauge hooked up. I did tear down the original tansmission that the truck came with. I kept it after I put the new one in over a year ago. It's on the bench now.....had a broken sun shell in it, although it never lost reverse, 2nd, or OD. It broke the splined flange off, leaving the about 1/16" of splines remaining to engage the shaft, and that was enough to hold. (a testament to how easily I drive this ole truck) I had to fabricate a puller to get the spring pack and low/reverse piston out. (I'm a toolmaker by trade? I have the ATSG manual, and I guess I will attempt to figure out what's broke in the "new" trans in the truck. I just would likek to know all I can before I pull it out and disect it.
Thanks guys.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 10-13-2009, 01:36 PM
Registered User
 
Join Date: Oct 2009
Location: Indiana
Posts: 28
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
OK, got the gauge hooked up today.
65 lbs, in Park, Reverse, although it isn't actually going into reverse, Neutral, or any forward gear, at IDLE. When I shift into Reverse the gauge does dip maybe 5 lbs and then bounces right back to 65.....fast as an eye blink.
In Neutral, reving to 2500 rpm the pressure goes up to 85 lbs.
In a forward gear, if I hold the brake and lightly gas it, it'll go to about 150 lbs. Driving in a forward gear, any gear, and the pressure only slightly rises, hardly detectable.
When I shift in and out of reverse, if it catches , it'll bump to about 85 lbs. Backing up, kinda shudders.....it'll hold 85 lbs.
Any ideas???
Thanks, T00lmanii

edit....I am no way saying any of this is the fault of the builder. I'm just adding this info in case some of you might be familier with this company's transmittins.
It's a "heavy Hauler" series from PerformaBuilt, out of Pa. (The Beast sunshell, corvette servo, heavy duty wide band, heavy duty pump with staked bushing, 4th uses a sonnax dual piston servo, etc etc...)

Last edited by t00lmanii; 10-13-2009 at 04:00 PM.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 10-13-2009, 09:51 PM
Crosley's Avatar
Hotrodders.com Moderator
 
Last wiki edit: T-350 rebuild tech
Last journal entry: Bar under the dash
Last photo:
Join Date: Nov 2002
Location: ... USA
Posts: 7,980
Wiki Edits: 1659

Thanks: 257
Thanked 85 Times in 82 Posts
85 psi in reverse is a bit weak.. That should increase if you throttle up.

The shutter is from a clutch pack not holding.

there is a problem with the low-reverse or reverse input clutch packs.
__________________
Some people are like Slinkies... Not really good for anything, but they still bring a smile to your face when you push them down a flight of stairs.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 10-14-2009, 11:13 AM
Registered User
 
Join Date: Oct 2009
Location: Indiana
Posts: 28
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Crosley, thanks for your guidance. I guess I'll try to get this thing pulled out this weekend and see what I find inside.
I did take it for a longer drive today with the gauge. After getting up to temp the pressure in reverse did rise from the 85 psi I reported yesterday. IF it does go into reverse, I can back up hard and it;ll go to 150, sometimes higher. Still has that slipping/shudder though, even at the higher pressure. Here are the results of the gauge readings today..........
At cold startup, and after up to temp...
At idle, P,N, 3rd and 1st.......58-60 psi
When put in 2nd it is 58, but will jump to 80 after a few seconds.
When put in R it is 58, but will SLOWLY rise to 65.
Normal driving from a stop in OD gets a rise to 100psi in each gear
Hard accel from a stop in OD gets 150 psi in all gears.
Thanks again for all the advice, and I'll post back what I find.
Toolmanii
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 10-18-2009, 12:18 PM
Registered User
 
Join Date: Oct 2009
Location: Indiana
Posts: 28
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I pulled the tranny yesterday and got it partialy torn down. I did find the 3-4 accumulator piston and spring in upside down, according to the diagram I was looking at. The spring was in the case first, with the piston on top of it(upside down). The diagram I have shows the piston going in the case first, with the 3 "fingers" up, then the spring, with the spacer plate holding everything in. Is my perception correct? What would this condition result in? It's kind of making me skeptical of the whole rebuilt tranny I may have. I did an air check of the low/reverse piston and it seemed OK, but I'm going to put together the original transmission I still have....starting from the ground up.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 10-18-2009, 12:34 PM
Crosley's Avatar
Hotrodders.com Moderator
 
Last wiki edit: T-350 rebuild tech
Last journal entry: Bar under the dash
Last photo:
Join Date: Nov 2002
Location: ... USA
Posts: 7,980
Wiki Edits: 1659

Thanks: 257
Thanked 85 Times in 82 Posts
Quote:
Originally Posted by t00lmanii
I pulled the tranny yesterday and got it partialy torn down. I did find the 3-4 accumulator piston and spring in upside down, according to the diagram I was looking at. The spring was in the case first, with the piston on top of it(upside down). The diagram I have shows the piston going in the case first, with the 3 "fingers" up, then the spring, with the spacer plate holding everything in. Is my perception correct? What would this condition result in? It's kind of making me skeptical of the whole rebuilt tranny I may have. I did an air check of the low/reverse piston and it seemed OK, but I'm going to put together the original transmission I still have....starting from the ground up.

did you air check the reverse input clutch pack?

did you air check both sections of the low - reverse piston?
__________________
Some people are like Slinkies... Not really good for anything, but they still bring a smile to your face when you push them down a flight of stairs.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 10-18-2009, 02:38 PM
Registered User
 
Join Date: Oct 2009
Location: Indiana
Posts: 28
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by Crosley
did you air check the reverse input clutch pack?

did you air check both sections of the low - reverse piston?
Crosley, No....haven't airchecked the reverse input clutch pack....
both sections?.......ummm...no......I didn't realize there were 2 sections. Could you explain the check?
Thanks, Louis
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 10-18-2009, 04:28 PM
Crosley's Avatar
Hotrodders.com Moderator
 
Last wiki edit: T-350 rebuild tech
Last journal entry: Bar under the dash
Last photo:
Join Date: Nov 2002
Location: ... USA
Posts: 7,980
Wiki Edits: 1659

Thanks: 257
Thanked 85 Times in 82 Posts
Quote:
Originally Posted by t00lmanii
Crosley, No....haven't airchecked the reverse input clutch pack....
both sections?.......ummm...no......I didn't realize there were 2 sections. Could you explain the check?
Thanks, Louis

You said you air checked the low - reverse piston apply. there are two sections to the piston. the holes are next to each other for fluid transfer to each piston section.

I would suggest checking via air both of these sections
__________________
Some people are like Slinkies... Not really good for anything, but they still bring a smile to your face when you push them down a flight of stairs.
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 10-18-2009, 09:15 PM
Registered User
 
Join Date: Oct 2009
Location: Indiana
Posts: 28
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Crosley....ok, checked the low/reverse via both ports and seems OK. I took what you said to mean that the piston would move in 1 stage and then more travel in 2nd stage. At any rate, it moves the Max amount through both ports. I WILL pick up the ATSG manual tommorrow. I downloaded a 186 page rebuild manual off the net, which the poster thought was the ATSG manual, but it lacks the specs and part nomenclature that I need.
I went back to the shop this evening and did some more clean-up and checking of parts. Here is what I've found that may be the bleed on the reverse circuit. The stator shaft tube has severe wear as does the bushings in the reverse input drum. The bushing measures 1.767 and the shaft tube 1.731 The smaller bushing and shaft diameter also have severe wear.
The reverse input clutchpack (steels and frictions) and the low/reverse clutchpack both measure about the same as the ones in my original transmittin that has 197,000 on it.
There are some other issues that I have questions about, but I'll make them another thread in the future. They have to do with what mods would be benificial to a trans for towing.
Thanks again for all your guidance.
Reply With Quote Quick reply to this message

Recent Transmission - Rearend posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
4l60e 4x4 problem. Loud Clicking!! 327amc Transmission - Rearend 28 02-23-2012 10:09 PM
86 Dodge 4x4 727 tranny no reverse after loud metallic pop sound? mike 96 ws6 Transmission - Rearend 4 03-14-2006 11:43 AM
4L60E 4x4 tarmon8r Transmission - Rearend 0 03-10-2006 07:47 PM
99 tahoe 4X4 - lost overdrive & reverse tank2323 Transmission - Rearend 1 12-27-2002 04:20 PM
77 Suburban K-20 4x4 roof skins 01SSCamero Body - Exterior 2 12-10-2002 09:30 AM


All times are GMT -6. The time now is 09:19 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.