Chevy & GMC Vans

No. Just the pan.

For now, just tow with tow/haul on and plan to get the cooler, fluid and filter done asap.

OK, I'd like to find the time in the next weekend or 2

Where is this spring located? and how do I replace it?
Is it a dealer item? Do u already have a part number for it?

How much fluid do I need and what type does the astro take?
I plan on dropping the pan, replacing the filter and adding a cooler I already have.

Thanks for all the help.

I don't have a clue on the part number. I just remember we went to a tranny shop and asked for a 700R4 inner pump spring, paid them the $1 and walked out! LOL We then dropped the pan, filter and valve body to get to the TCC servo. Once that was out, we just replaced the small stock spring with the new longer, stiffer spring. This was done before I had a digital camera so I don't know where the servo is and a buddy of mine was mostly doing the work.

You will need around 8-12 quarts of Dexron 3 fluid.

I bet you will find by changing the fluid and filter and installing a cooler, you won't need to do the spring.

Thank you all for the replies. Ive been trying to find the time to get this repaired and its just not easy. I stopped at a local tranny shop this morning, told him the symptoms and he is aware of the very common problem in these transmissions, but told me it would cost me $400.00 at his shop, plus $60.00 - $100.00 to install the cooler. Also he will not sell me the parts. The 400.00 would also include a tranny service, which I assume is not a flush, but just the pan dropped and new fluid and filter.

I am in the process of getting the name and number of another tranny shop my friend recently used to see what price he gives me.

He told me the parts are only available at a dealer and I would have to but the whole valve body for around $700.00.

Does any one here know where I can get the parts for this repair if I decide to do this myself? He refered to it as a valve body update. Can they be ordered online? Part numbers any one? Is there a TSB number that I can use at a dealer to get just the parts I need and not an entire valve body?

Thanks again, you've been very helpful.

OK, after posting and re-reading I see that Lagrasta posted a site that sells tranny parts, Thanks. Now I need to know what tranny I have in this astro. The paper work I have just says 4 speed over drive. no info under the hood or in the console that says what it is.

Thanks again

4L60E

I went back and searched through some old archives and found a repair that was posted by a GM tranny tech, BIGAT on the old board. Here is the pic and the repair:

Posted on: Nov. 23 2004,20:03 by BIGAT
An oldie but a GOODIE, this has worked everytime I have used it.
DTC 1870 and harsh shifts '96-'01 4L60E Mod


Drill a .032" hole thru bore plug 381 to provide a drain for fluid
buildup past the 380 valve from wear in the bore. I use a 1/8"
bit to drill @ 1/4" into the plug and then finish the hole with
the .032" drill carefully as the small bit is very fragile.The plug is
@ 1/2" - 5/8 " in depth.The fluid build up actually reduces TCC apply
pressure causing the TCC slip speed to exceed the parameter allowed in the
PCM calibration and sets DTC P1870 which forces full line pressure and the hard shifts.
Once you see fluid come out of the hloe while drilling, you're thru.
This drain has no other effect on trans. operation but IS not a GM approved repair.
They want to sell you an updated v.body which has been updated @ least 5 times
and costs @ $245.00 - $285.00

Posted on: Nov. 24 2004,16:08 by Intenseman

so why is that 96 and up? Do the earlier 4L60Es have a different valve body?

Posted on: Nov. 25 2004,05:27 by BIGAT

The v.bodies can be different in different applications in the same model year. I beleive it was engineering oversite with the TCC being PWM controlled causing the valve to vibrate and wear the valve and bore enough to cause the problem because the updates all had different valve designs to stop the movement of the valve when it is applied but it seems there is no permanent fix as of yet. (IMO)

Posted on: Dec. 12 2004,05:36 by BIGAT

The hole mod to the bore plug has fixed everyone I have encountered. If there is no slippage in od 4th gear, the mod will work. If you find excessive metal or clutch material in the pan, there may be internal leakage. For the ease of the mod, I'd try it anyway.

Posted on: Dec. 12 2004,06:06 by _crawford71

I have been hearing about a sonnax tcc reg valve kit that has been created to fix this problem. any opinion on sonnox part? to answere your question, I havent noticed any slip in od. nor was there any excessive clutch residue ,and no metal was found in fluid or on magnet. because the valve body is new and tcc valve has no wear, what else could cause this problem. and am i putting to much faith in gm remanufactured parts?

Posted on: Dec. 12 2004,06:31 by BIGAT

A worn TCC clutch in the Torque converter, the o-ring seal on the input shaft, the oring seal on the TCC apply solenoid and/or a leaking TCC apply solenoid could cause the TCC to slip. Do you have access to a scanner so you can look at TCC slip speed while driving with the vehicle hot. It should stay under 100 rpm on a steady cruise with no load. If it goes up and down over 100 rpms, then the TCC is the system to look at. The sonnax kit is supposed to repair the wear problem at the TCC reg. apply valve. I haven't tryed it or know of anyone here that has.

So, drilling a hole in that valve that is circled (381) may fix my problem?
How hard is it to get the valve body and that valve out?
I have removed a valve body before, it was just a few screws, messy but not to hard.
Looks like a clip holds that valve in?

Thanks again for all the info.

I almost think you can drill the hole in that plug with the VB installed. You just need to remove the pan and see. The VB is easy to remove, you just need to be careful of where the check balls are and don't tip over or drop the VB! The bolts holding it in go in a certain spot. I will see if I can come up with photo's showing what bolts to pull and the torque specs.

Your the best!!

Yeah, those little balls can be a problem, thats what Im mostly worried about.

Here they are... Oh and you can use vaseline instead of TransJel

Right out of the ATSG manual..





Check ball locations...



Bolt locations and sizes...

Glad to see my link was of help.

I'm following along with this intended mod...

Thank you for posting the info. Now Im back to trying to find the time, and Im concerned that this may be beyond my skill level. Either that or pay $400.00.
Tomorrow I will contact that other shop to see what they say.
Thanks again.

Check you separator plate. I would expect you will find some wear where the balls hit the separator plate.

I had the P1870 on a 97 Astro. I replaced the separator plate and did a shift correction kit. After doing the job myself and seeing the success when finished I would do it again. Were I to have the same problem on my 2002 Safari, I would check the separator plate for wear before doing the shift correction kit. I really believe the problem is related to pressure problems caused by improper closure at the separator. Just my thoughts.