This Blazer 4x4 with 270,000 miles was purchased with a tranny that won't go on reverse. Seller said it happened suddenly and it makes no noise when driving or put on reverse. Any idea on how to check if in fact I have to fix internal damage or change the tranny? Does the Blazer tranny have a computer component that may cause this?

 

Would almost bet you have a broken reaction sun shell, if thats the case you will only have 1st and 3rd in forward gears, you will not have reverse, 2nd or 4th tho. If you have all forward gears 1-OD then I would bet it would be your reverse clutch pack

 

what does the transmission fluid look and smell like?

 

Thank you Nvidia78 and blazerpower. Nvidia78, the Blazer is an LT model, it has
P N R D 3 2 1. All forward gears engage properly, except, for Reverse. I didn't notice if it has and an 'overdrive button'. On the "reverse clutch pack", is it located in the Transmission Oil Pan area? I feel like I'm having an "Iowa Caucus".
Blazerpower, I haven't checked the trans fluid yet. Is there anything unusual (other than metal dust) I shouold be looking for in the fluid?

 

Not that easy, the reverse clutch pack is in the transmission, it will have to be pulled apart to fix that, might as well do a rebuild then as it is apart, the only thing accessible in the pan area are the valve body and shift solenoids.

 

Here is the symptom related possible causes for a no reverse condition:

 

Hi Nvidia78, I've been doing some research on rebuilding this tranny when I can get to it.
I found this web site: www.transmissioncenter.net/tools.htm looking for prices on tools for the job. I'm sure I'm going to need the spring compressor, drum install tool, and snap ring removal tool. The price for them are okay.
There are tools for the Stator Shaft seal installer/ resizer, Forward and Overrun clutches inner lip seals. Do I really need these tools? Can I do the job without them and do I really need to change these parts at all. So far, I calculated that all these tools would run around $325 which ain't bad considering the alternative--tranny shop. thanks again Nvidia78. By the way, I see it's cold down your way.

 

Yeah its cold here, cant wait for spring already lol. I have never rebuilt a tranny myself, would be something I would love to try but since I live in an apartment and no place to do it really sucks. I would go ahead and get all the tools, and when you are rebuilding it you will find out which tools are needed and what tools you can live without. I have heard the stator shaft seal can be a pain in the a** to fit. And the tools that you dont need you can resell on ebay or something and get almost full price out of. I have been told that rebuilding a tranny is easy just lay everything out in the order you pulled them and make sure you do not forget a snap ring. also make sure and get the Beast sunshell. I have also seen videos on youtube where someone rebuilt a tranny in the driveway and used no tools and it required freezing of certain parts in order for them to shrink enough to put together