What do you guys like to add to your ATF to help out an aging trans?
CK5
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ATF additives
- Thread starter BGKYK5
- Start date
4xcrazy
3/4 ton status
Nothing, mainly a lighter foot and modified driving style to prolong the life of the trans. 
trans-x or bg additive is about the only things i would trust.
DeviousK5
1/2 ton status
Lubeguard. the red bottle or the platinum(silver). It isnt intended to be any sort of leak fix or slip cure, those are garbage for the most part. The stop leak/slip fix in a bottle usually contain lots of solvent which in the long term eats the seals. lubeguard will lower the temp of the trans round 20-30 degrees and is more of a protectant. I many years ago had a sticky TCC solenoid in my 95sedan deville and used a lucas additive, it was syrup in a bottle and it did free the solenoid.
Cornfield creations
1/2 ton status
Yeup, what devious said, Lubeguard would be the only thing I would put in there. It will lower the temp and also help the fluid to maintain viscosity during it's life.
Don't use the lucas/ stop leak stuff. We have seen it clog fluid filters in the trans.
Don't use the lucas/ stop leak stuff. We have seen it clog fluid filters in the trans.
I put a bottle of Lucas in the th350 on my 72 about a 12,000 miles back. Stopped the leaks, shifts good, no complaints in about a year and a half.
DeviousK5
1/2 ton status
The Th350, and th400 don't have a cotton filter , whereas a 700-R4/ 4L60E, 4l80E's,and allisons do. Cotton plugs up with that syrupy crap and the metal/or nylon filters in the older stuff doesn't seem to clog up because they dont filter as well. As far as longevity goes i can't speak as the caddy i used it on cracked its cylinder head about 5k miles later.
Smart blend is another additive lots of other shops i have worked at use,
and its good stuff too.
Smart blend is another additive lots of other shops i have worked at use,
and its good stuff too.
I've used Lucas and seen many others who have used it have minor miracles performed as far as solving the problem..but I wont argue that it could clog some filters in certain trannies,though I doubt after mixing a quart with 10 qts of ATF wouldn't thin it enough not to be an issue..
I have used Wynns transmission treatment and Gunk/SolderSeal brand "Trans-Kleen" and while it didn't hurt anything,they didn't seem to help much either..have heard good things about Lube Gaurd too,but never used it myself..I shy away from the "stop-leak" type of crap,its not good to use ,it can plug valve body passages and cause other woes,a pint of brake fluid added to the ATF will soften hard seals and do just as well,with no harmfull effects..
Years ago I had a TH350 in a '72 K5,and it refused to go into the forward gears when it was started in the morning or after sitting overnight,or several hours,especially in colder weather..it would back up in revrse fine,but you'd have to wait until the engine warmed up enough to move the temp gauge needle,then you'd feel it trying to go into gear several times,then it finally engauged--once it did,you could drive the dam thing to califonia & back and it shifted perfect,no slippage!..next day,the same thing--I was late for work so many times because of that tranny I almost got fired!..
I tried every additive we sold at the parts store I worked at and then some,changed the fluid & filter ,torqued the valve body bots,etc,to no avail..
One customer who was a long time mechanic suggested I put a bottle of Lestoil in the tranny,he claimed that he had heard that from a reputable tranny shop,that it cleans and frees up stuck valve body pistons,etc..I figured I had nothing to lose so I tried a bottle,and it didn't cure it,but it did seem to go in forward gears sooner than it used too,,and I bet I had the cleanest TH350 in town..but I ended up swapping a SM465 into the truck after my patience ran out waiting for "drive" to appear and getting up at 6 am to be on time for work at 8!..
I have used Wynns transmission treatment and Gunk/SolderSeal brand "Trans-Kleen" and while it didn't hurt anything,they didn't seem to help much either..have heard good things about Lube Gaurd too,but never used it myself..I shy away from the "stop-leak" type of crap,its not good to use ,it can plug valve body passages and cause other woes,a pint of brake fluid added to the ATF will soften hard seals and do just as well,with no harmfull effects..
Years ago I had a TH350 in a '72 K5,and it refused to go into the forward gears when it was started in the morning or after sitting overnight,or several hours,especially in colder weather..it would back up in revrse fine,but you'd have to wait until the engine warmed up enough to move the temp gauge needle,then you'd feel it trying to go into gear several times,then it finally engauged--once it did,you could drive the dam thing to califonia & back and it shifted perfect,no slippage!..next day,the same thing--I was late for work so many times because of that tranny I almost got fired!..
I tried every additive we sold at the parts store I worked at and then some,changed the fluid & filter ,torqued the valve body bots,etc,to no avail..
One customer who was a long time mechanic suggested I put a bottle of Lestoil in the tranny,he claimed that he had heard that from a reputable tranny shop,that it cleans and frees up stuck valve body pistons,etc..I figured I had nothing to lose so I tried a bottle,and it didn't cure it,but it did seem to go in forward gears sooner than it used too,,and I bet I had the cleanest TH350 in town..but I ended up swapping a SM465 into the truck after my patience ran out waiting for "drive" to appear and getting up at 6 am to be on time for work at 8!..
Trying to make the trans shift firmer or just worried about longevity?
A trick I heard when I had my '99 Ram was the Ram guys would put a small bottle of "shift improver" in their auto trans. It was a recommended part for the 94-whatever Dodge Ram SST's. Turned out it was just MOPAR's limited slip additive.
A trick I heard when I had my '99 Ram was the Ram guys would put a small bottle of "shift improver" in their auto trans. It was a recommended part for the 94-whatever Dodge Ram SST's. Turned out it was just MOPAR's limited slip additive.
Just want to make it last. The fluid gets dark real quick - I don't think the PO ever flushed it.
Kjunky5
1/2 ton status
Sawdust if your trying to sell it....Which trans are we talking about?
You wanna buy another 700R4 from me? 
J/K, not trying to sell it. This is the 700R4 from my '89 that is now in my '91 - in other words this is the "good" one - you got the "bad" one.
I want to make the trans last until I get around to a Gen III swap - probably in late 2015.
Or about the same time you finish your 5.3 swap.
J/K, not trying to sell it. This is the 700R4 from my '89 that is now in my '91 - in other words this is the "good" one - you got the "bad" one.
I want to make the trans last until I get around to a Gen III swap - probably in late 2015.
Or about the same time you finish your 5.3 swap.
Kjunky5
1/2 ton status
Hey Hey now
the short block is assembled and waiting on a cam not exceeding 0.551 lift and I've collected the correct TAC module and DBW pedal. The "bad" trans I got is now the "good" trans that was pulling the K5 around the last 2 years till I got the Sierra. We can fix that "bad" one easily. I still have all the tools. What are the symptoms?
the short block is assembled and waiting on a cam not exceeding 0.551 lift and I've collected the correct TAC module and DBW pedal. The "bad" trans I got is now the "good" trans that was pulling the K5 around the last 2 years till I got the Sierra. We can fix that "bad" one easily. I still have all the tools. What are the symptoms?
No real problems - it still shifts fine. Just worried about the dark fluid, I'm guessing it is clutch material in the fluid, so I'm just trying to keep it alive as long as possible. I don't really drive it long enough or hard enough to get it hot (though I still haven't hooked up the temp gauge 
). I've got to get the suspension done so I can wheel it a little before I have to start pulling it apart again.
). I've got to get the suspension done so I can wheel it a little before I have to start pulling it apart again.
Kjunky5
1/2 ton status
I'm assuming the TV cable is adjusted but the 3/4 frictions are (92% of the time) the first thing to go. The others are the 2-4 band and the sun shell. The 3/4 usually let go once you reach the furthest point from home....
Yup, I double checked the TV cable. I may keep it out of OD to help make it last too (especially when far from home).
Kjunky5
1/2 ton status
If Scottys was still open they carried Lubegard brand stuff. Now I don't know where to get any. Just wheel it till it breaks. Good thing is you stay in first or second when wheelin. Not enough room to get any faster, at least not at Wishbone.
I won't make the July 17-18th event at Wishbone, but I plan to make it to whatever the next one is.
Kjunky5
1/2 ton status
Make it to the next one?...Gee..never heard that one before.
This time I mean it.....
mostly....
unless something else comes up....
or I don't get off my keester and get my junk together.....
mostly....
unless something else comes up....
or I don't get off my keester and get my junk together.....
