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4R70W Build Progress and questions

JSmall

Bronco Guru
Joined
Feb 18, 2004
Messages
3,223
I decided to replace my ZF with a 99 4R70W and an Atlas 4 speed tcase. I will use this thread to document the rebuild of the transmission and to ask questions when I get hung up ;D

I used the rebuild list supplied by Phil in a different thread and added a few things to it that I will need.
ivkwZAn.jpg


Few pics from the disasambly
rw6NZMG.jpg


FJ8G0E5.jpg


All the sub-assemblies removed and ready to be cleaned
TGmyzWx.jpg


The direct clutch steels and fibers don't look good. The outer piston seal was damaged when I removed it so I assume that was the cause of the damage.
9yDi9B9.jpg


I'm waiting on parts right now so I will update as they come in.
 
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JSmall

JSmall

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Ran into the first small issue. The clearance between the end plate and snap ring should be between .060" - .091" and I have .054" max right now. Do I have any options? I have read that there are thinner snap rings to solve this issue, but I can't find anything that will work in my search.

Current snap ring .0635"
Current end plate .2375"

Ev0weUr.jpg
 

jagbucket

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Aug 9, 2013
Messages
251
Buy extra lip seals and rings I messed up several and had to wait on mail as no one would sell just parts I needed locally. They do not cost much but can add weeks to your build.. i never messed with these before and you may be more adept but i found piston seals and shaft seals the hardest part of the build
 

Viperwolf1

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electron whisperer
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Aug 23, 2007
Messages
24,316
Ran into the first small issue. The clearance between the end plate and snap ring should be between .060" - .091" and I have .054" max right now. Do I have any options? I have read that there are thinner snap rings to solve this issue, but I can't find anything that will work in my search.

Current snap ring .0635"
Current end plate .2375"

Get a couple 76126B thinner steels. Replace the one next to the piston and the one next to the pressure plate. Don't put thin steels in the middle of the pack.
 
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JSmall

JSmall

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Messages
3,223
Get a couple 76126B thinner steels. Replace the one next to the piston and the one next to the pressure plate. Don't put thin steels in the middle of the pack.

I knew you would have the answer if you saw this :cool: Thank you very much!
 
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JSmall

JSmall

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3,223
Rebuild parts have started showing up. The thinner steels should be here Thursday so I will be able to continue the build. I'm taking the housing to the trans shop so they can hot tank it.

lR86EEF.jpg
 
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JSmall

JSmall

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3,223
I am curious if I purchased the wrong Sonnax kit.

I purchased PN SC-AODE-4R75E and that includes oversized Pressure Regulator & Boost Valve Kit. Both of those require special tools and reaming of the valve body. Is this the kit that I should have purchased? The few 4R70W rebuild videos that I have watched do not show any reaming of the VB.

I'm guessing I should have purchased the Zip Kit AODE-4R75E-ZIP which doesn't require any special tools or reaming.

Thoughts?
 

Viperwolf1

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Sorry, my fault. The original sure cure kit didn't have oversize valves. They quit making that kit some time back and replaced it with the zip kit. This is the first time I've seen this new sure cure kit. I saw the link to summit from your spreadsheet and assumed it was old stock of the original kit.

Here are the standard sized parts.
Sonnax main pressure reg valve 76948-09
Boost valve 76948-02K
 
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JSmall

JSmall

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Feb 18, 2004
Messages
3,223
Sorry, my fault. The original sure cure kit didn't have oversize valves. They quit making that kit some time back and replaced it with the zip kit. This is the first time I've seen this new sure cure kit. I saw the link to summit from your spreadsheet and assumed it was old stock of the original kit.

Here are the standard sized parts.
Sonnax main pressure reg valve 76948-09
Boost valve 76948-02K

No problem at all! I will try to replace my kit with the Zip kit and if Summit won't replace them, I will order the standard sized parts you have listed. Thanks?
 
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JSmall

JSmall

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I sent the Sure Cure Kit back in exchange for the Zip Kit. That’s going to delay the progress for now... oh well.

The reverse clutch Belleville return spring has a snap ring that is a real PITA!!! I think I spent 20 minutes trying to get it installed.

One more piece showed up today
 

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904Bronco

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Jaromy,

Consider puting a 1/8" port in the pan, so you can add a temp sender. Messy to drop the pan to do so later... :cool:
 

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Viperwolf1

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Jaromy,



Consider puting a 1/8" port in the pan, so you can add a temp sender. Messy to drop the pan to do so later... :cool:
This is my preferred location. I use the B&M drain plug kit and weld the nut inside the pan. The plug is 1/8" npt and can be substituted for an additional temp sensor if you use a dedicated trans temp gauge. Location is good because it allows most of the fluid from the pan to drain.
ee3a26b60ee043fa41557686ced7fb95.jpg
 
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JSmall

JSmall

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Feb 18, 2004
Messages
3,223
Jaromy,

Consider puting a 1/8" port in the pan, so you can add a temp sender. Messy to drop the pan to do so later... :cool:

Good idea! I have a new pan with a drain in it so I’ll look into adding a temp sender.

This is my preferred location. I use the B&M drain plug kit and weld the nut inside the pan. The plug is 1/8" npt and can be substituted for an additional temp sensor if you use a dedicated trans temp gauge. Location is good because it allows most of the fluid from the pan to drain.
ee3a26b60ee043fa41557686ced7fb95.jpg

The pan I got from O’Reilly’s has the drain in that same location.
 

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JSmall

JSmall

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Is it a good idea to replace the forward and direct clutch drums when rebuilding? I stopped by the trans shop to have the housing cleaned in their hot tank and the shop manager suggested new ones. I trust him so I figured I should ask.

Sonnax has some expensive options that look nice. Not sure they are needed for a low HP build, but I’ll purchase them if needed.

https://www.sonnax.com/parts/4646-smart-tech-direct-clutch-drum-shaft-kit
 

Viperwolf1

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You only need to replace them if they are damaged. Look for cracks near the snap ring grooves, cracked welds and ridges worn into the drum by the steel plates.
 
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JSmall

JSmall

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3,223
You only need to replace them if they are damaged. Look for cracks near the snap ring grooves, cracked welds and ridges worn into the drum by the steel plates.

That is what I was going to do and I inspecting them very well. They look good to me so I was going to use them as is. He mentioned replacing them anyway so I figured I would ask.
 
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JSmall

JSmall

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Does the stock torque converter need to be replaced or refurbished? I am not even sure having a stock TC rebuilt is an option... lack of knowledge for sure :-[

If it should be replaced, should I be looking at a specific stall?
 

Yeller

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yes converter should be replaced with a referbed stock one. Not sure what your specs are but unless you went pretty far out there on cam in the engine it will be fine.

I do have a question and mostly want to know since I get asked "What should I do?" so often. Why 4spd Atlas? With a modern 4spd auto with correct axle gearing and 2.7-3.0 tcase gearing, I have not found the need for the extra reduction, and I you know how dumb I can get doin stuff, at times the more technical and difficult the happier I am. I'm not doubting your decision, just would like to hear your reasoning and thoughts.
 
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JSmall

JSmall

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3,223
yes converter should be replaced with a referbed stock one. Not sure what your specs are but unless you went pretty far out there on cam in the engine it will be fine.

I do have a question and mostly want to know since I get asked "What should I do?" so often. Why 4spd Atlas? With a modern 4spd auto with correct axle gearing and 2.7-3.0 tcase gearing, I have not found the need for the extra reduction, and I you know how dumb I can get doin stuff, at times the more technical and difficult the happier I am. I'm not doubting your decision, just would like to hear your reasoning and thoughts.

I went with a stock rebuild and cam on the 5.0 so I guess I should be good with the stock stall.

Should I be looking at a specific brand or just find one that has been rebuilt from a local trans shop?

I am not 100% on the 4spd. I still have a lot of reading to do and questions to ask. My initial thought was the split between low and double low looked good for all situations.

4R70W/3.8 Atlas/5.13 gears/38" tire = 55.4 crawl ratio. I know this is right around what you are thinking is ideal for a crawler. I know Brian is going through this decision as well. How well will this work in the sand? I don't have anywhere near the HP that Brian has so I am sure I would need to be in low range while playing? Is this the preferred ratio for obstacles in Moab, Rubicon and TSF? These are the questions that I ask myself and others.

4R70W/2.0/2.72/5.44/5.13 gears/38" tire = 29.1, 39.6, and 79.2 options. Other than driveline length, is there a drawback to going with the 4spd? Will having the added options benefit me in any way? This is my thought process right now. I know we discussed this a little while in Moab. I am always willing to listen when you're giving advice :cool:
 

Yeller

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I'd pick one up local, but someone may have a better idea or experience, did trans work for 10 years, but been long enough all my contacts have all moved on.

In my opinion running an auto is far and away more forgiving than a manual. With a manual I like the 55-70:1 range, with an auto 35-45:1 is my preference. I think being stuck with 55:1 you'll hate sand, mud, or anything that requires wheel speed. Even with my LS I run low in sand if i'm really ripping on it in the dunes, at 41.7:1 for a crawl ratio with the overdrive 50mph is easy, gps verified as fast as 72. Everyone (especially bronco guys) is used to playing with a c4 and a dana 20 or a zf/435 and both wishing for more and more options because they are either so high its unusable or so low its unusable. so they go to a 4spd auto and 3.8-5.0 tcase and then wish they could have more wheel speed, when they don't need near that much gear a 3.0 would be a perfect compromise. A little perspective, running the 4r70 with a 3.0 is virtually equal to running a c4 with a 3.8. unlike what most preach here about diff gears "Don't fear the gear" imo tcase gears with an auto should be way more modest. You will still have the control your after and be able to rip on it when you want. You will also break fewer parts, you can feel the drive train load up, with too much tcase gear you cannot or its much more difficult. Learn to drive with both feet, modulating the brakes at the right times can make some amazing things happen with amazing control;)
 
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