01 Blazer tranny problem

I am working on a 2001 Chevy Blazer and I am pretty sure the sunshell gear has gone out on it, NO Reverse revs very high before shifting. Well he got another transmission with the exact same problem. So I really just want to know how har is it to replace the sunshell gear?

If you have some knowledege on the transmission and are comfortable with working on one, its not that bad to replace it. If your there though, you might as well do a rebuild on it and replace the fritcions and soft parts.

I am a mechanic, I have rebuilt engines, axles, transfer case, but have always kept away from auto transmissions. I seen a brief write-up with some good picks of a teardown of this tranny. it actually doesn't seem to hard to rebuild. Are there any special tools that are absolutely necessary to do the rebuild?

Hello Joe, it's really fairly easy to rebuild one of them. The first time is kind of confusing but after that no sweat. Now, to answer your question about special tools. I would recommend buying the rebuild DVD that is floating around on the web. Invaluable for first time. I also bought the AFTS? or something like that, rebuild manual. They were around $25 apiece. I also bought a transmission jack from harbor freight for around $60. There are a couple of special tools you will need, one being the teflon seal re-sizers (two sizes.) These seals are on the input shaft and need to work. Now, I discovered that if they "look" OK you are probably better off leaving them on rather than trying to re-size them with tape or something. Someone else might have a suggestion for doing this without these tools. The problem is that when you slip them down the shaft to fit into grooves they stretch out of shape and need to be back to original size so that you can fit the front pump onto them and get a good seal. The only other special tool can be fabricated. It is the spring compressor. By drilling a couple of holes in your workbench you can make a tool with a steel bar, a nut welded on in the middle, and some washers, nuts, and all thread. You'll figure it out once you see how it works. Also, you will need an air compressor and regulator so that you can check piston/clutch activation before re-assembling.....a MUST.

Otherwise it was really easy and you can save a bunch of money...I had about $500.00 in mine including the jack, book, and DVD. I will reiterate...you need the DVD.

Good luck and have fun. I did.

Lynn Wagoner
Yukon, OK

It's an ATSG (automatic transmission service group) manual.

You can get one on eBay or at http://www.transmissioncenter.net/4l60e.htm - I think they still have them.

Another special tool you need is the release tool for the transmission lines,the 3/8 release tool.The fittings are not a flare nut and are called a Jiffy tite fitting.The pain in the but way is picking them out with a pick or small screwdriver losing the little clipsAnother thing,in the direct drum are 5 black springs and there is one thing to do with them: THROW THEM AWAY!The aftermarket says to throw them away which they are right and GM says to put them back in.The problem with those 5 black springs is that they restrict the clutches from floating and burning them up.

wafrederick: I have the jiffy tite fitting tool and I know what you mean about using a pick, I did this for along time before getting the tool...lol

lynndiwagon: I plan on getting an ATSG manual from monster transmission, this is where I plan on buying the new Sun Shell Gear, Tq Converter, and rebuild kit as well. The compressor is not a problem already have that. As for the Teflon Seal resizer tool - does anyone know where I can find this tool at?

You do need a special torx bit,a T50 torx plus bit and heat the bolts for the bellhousing up with a torch which the bolts are locktited in.Kent Moore,whom makes GM's specialty tools does sell the teflon seal resizer tool getting it from the dealer.

I got torx bits. thats no problem. How much is the Teflon Seal Resizer?

Call around for the price,even at the dealer.The dealer might give you Kent Moore's number.

What is the black box on the driverside of the transmission (the shift lever goes through it) called? I had a problem getting the electrical connectors off and apparently the person who to the used tranny out of the other vehicle did too because they broke it. Well it looks like they glue the connectors into place....lol Anyways I need to know what it is called so I can find another one. Also anyone know the trick to getting the electrical connector off without breaking them?

What is the black box on the driver side of the transmission (the shift lever goes through it) called? I had a problem getting the electrical connectors off and apparently the person who to the used tranny out of the other vehicle did too because they broke it. Well it looks like they glue the connectors into place....lol Anyways I need to know what it is called so I can find another one. Also anyone know the trick to getting the electrical connector off without breaking them?


Yes they are glued in for sealing.:lol: :lol2: :banghead:

Sometime heat will help.
But best to just leave them plugged in and unbolt the switch from the side of transmission.

Park/neutral position switch should name it.

A new on may come with a plug wiring kit if not you will usually need the plug wiring kit to.

The teflon seal resizer is expensive and you will need two of them.
For a one time deal see if a transmission shop will install them for you.
Good Luck

I remembered one more thing you will need. When you dissamble the pump, it will come apart in two halves, you will need something to realign the halves when putting back together. They make a big wide steel band that goes around the assembly to make sure everything is even. Of course I didn't have one so I went looking for a big hose clamp. Couldn't find one long enough so I ended up using one of those big nylon tie wrap things they use in heating and airconditioning to hold flexible ducts to fittings. It worked perfectly.

Yea NSS was the only thing I could come up with too because of it's location with the shifter lever but usually they only have a single (3-4 wire) connector.
Thanks for the info.

Lynniwagon - what about using multiple hose clamps and connecting them together?

That might work but they don't give those big hose clamps away. I think the nylon tye strap was about 1.00.

You might want to browse my crude web pages on the repair procedure:

4L60ERepairs (http://72.19.213.157/files/4L60ERepairs.html)

I've found a petty good tool for aligning the pump case halves when assembling the pump:

http://72.19.213.157/files/4L60EPumpBodyAlignmentLg.jpg

Get a 24" piece of flat stock about 1" wide (or wider) and fold some tangs (as shown in the foreground) in your bench vise or brake. A single clamp of any kind will easily align the halves while you bolt them.

I would also strongly urge you get a factory or ATSG manual specific to your transmission, and arrange a place to get repair parts before you begin. Many regular auto parts store do not stock transmission parts. If the vehicle has near 100K miles, consider a new separator plate and new or remanufactured torque converter.

What is the black box on the driverside of the transmission (the shift lever goes through it) called? I had a problem getting the electrical connectors off and apparently the person who to the used tranny out of the other vehicle did too because they broke it. Well it looks like they glue the connectors into place....lol Anyways I need to know what it is called so I can find another one. Also anyone know the trick to getting the electrical connector off without breaking them?

There was a TSB about the neutral safety switches on these, and many other vehicles. There was an issue where these switches would heat up as a result of a hot transmission and the heat would melt the glue from the switch and it would melt out to the connector, glueing the pieces together. When someone would come along to unplug the switch, they would try to prug the plug out and damage the switch, casuing shifting problems etc. If you damaged it, just replace it, they are about $50 or so.

lynndiwagon - well I work at a repair shop and we have a bunch of hose clamps

Blue Bowtie, those were good instructional pages and I used them, along with the manual and DVD, to successfully rebuild my 4L60E. All will benefit.....Thanks

The neutral safety switch is not cheap,about $180.00 for it and it is an AC Delco