mix conventional tranny fluid with synthetic?

JRJ04

Senior Member
Joined
Jun 18, 2007
Messages
1,737
Reaction score
4
Location
Houston, TX
at 100k i had my tranny drained and im pretty sure they didnt flush out the TC. At that time, Royal Purple was added to it. It has been running great since then. Probably time to flush it again.

Point im making...yes you can mix it.
 

MJ Synthetics

Full Access Member
Joined
Mar 11, 2009
Messages
173
Reaction score
0
Location
So Calif
Mixing fluids is not an issue when the fluid is in good shape. If the OP has let the trans go so low that it broke something then I wouldn't be doing anything but changing every drop in that trans but that is me.

Mixing fluids will not change the viscosity of the fluids if the fluids being mixed are of the same rating for that spec. So if your trans takes Mercon and you use a fluid rated for Mercon specs your fine mixing it whether its syn or dino.

Think about this...........when fluid gets old it loses viscosity. Lose to much viscosity and its trashed fluid. You drain the pan and put in fresh fluid your changing the viscosity of the fluid in the trans by adding fresh fluid, you are raising the overall viscosity in the fluid.
 

94f450sd

certified nutjob
Joined
Oct 13, 2005
Messages
2,323
Reaction score
0
Location
plymouth,ma
didnt even know it was low.i have never had a drop of tranny fluid under this truck.no tranny leaks at all.everytime i checked it,it was full.stupid me took it to the thanksgiving day burnouts.the fluid that is in it is blacker than my tires.and thats after dumping 1 1/2 gallons of fluid in it.itll back up all day long,burn the tires of it in reverse but barely moves in drive.put it in 1st manualy and itll move but just a little too much throttle and it slips.it was shifting hard and now it shifts but acts like its in neutral.so i most likely smoked the tranny anyways.but im gonna try a fluid and filter change and see what happens.gonna drain the converter and pan and let it sit over night with both plugs out.then im gonna coblle my air system back together to blow out the 2 coolers and shoot some brake cleaner through them and the lines.
 

MJ Synthetics

Full Access Member
Joined
Mar 11, 2009
Messages
173
Reaction score
0
Location
So Calif
didnt even know it was low.i have never had a drop of tranny fluid under this truck.no tranny leaks at all.everytime i checked it,it was full.stupid me took it to the thanksgiving day burnouts.the fluid that is in it is blacker than my tires.and thats after dumping 1 1/2 gallons of fluid in it.itll back up all day long,burn the tires of it in reverse but barely moves in drive.put it in 1st manualy and itll move but just a little too much throttle and it slips.it was shifting hard and now it shifts but acts like its in neutral.so i most likely smoked the tranny anyways.but im gonna try a fluid and filter change and see what happens.gonna drain the converter and pan and let it sit over night with both plugs out.then im gonna coblle my air system back together to blow out the 2 coolers and shoot some brake cleaner through them and the lines.

Rich,

You can do a fluid change if you want but I am going to guess 95% that it won't help much. The clutches are fried as well as the steels and possibly other things including the torque converter. If you want that baby to be back and for it to last it needs a rebuilt and if your doing a rebuild you might as well put in some quality stuff, beef it up and make it so you never have to worry about the burn out competitions and added power you may want to run in the future, just make sure to watch the fluid level.
 
Last edited:

JLDickmon

ursus combibo
Joined
Jun 22, 2006
Messages
4,173
Reaction score
12
Location
49041
I'd have to agree..
fluid changes are what you do BEFORE you have problems..
after that, you're herding cats...
 

94f450sd

certified nutjob
Joined
Oct 13, 2005
Messages
2,323
Reaction score
0
Location
plymouth,ma
Rich,

You can do a fluid change if you want but I am going to guess 95% that it won't help much. The clutches are fried as well as the steels and possibly other things including the torque converter. If you want that baby to be back and for it to last it needs a rebuilt and if your doing a rebuild you might as well put in some quality stuff, beef it up and make it so you never have to worry about the burn out competitions and added power you may want to run in the future, just make sure to watch the fluid level.

on edit.not trying to sound like a jerk,but read my signature.a stock tranny wouldnt last a day behind my motor.


im sure its cooked but a fluid change wont hurt to try.tonight its shifting,it was doing donuts this morning on the ice with no problem.

and i already spent the money on this tranny to be able to do whatever i wanted.i know it aint the best being a factory tech monster box.next time i spend that kind of money on a tranny im going to BTS.
 
Last edited:

Crumm

Fordoholic
Joined
Apr 17, 2005
Messages
5,704
Reaction score
5
Location
Fairbanks, Alaska
im sure its cooked but a fluid change wont hurt to try.tonight its shifting,it was doing donuts this morning on the ice with no problem.
You think it might last a little longer if you quit driving it like you were 16? Doing burn-outs is what got you where you are. Don't mean to sound like a jerk but for crying out loud Rich grow up a little if you can't afford to fix it. Walking ain't much fun when you have to do it to get where you are going.
 

94f450sd

certified nutjob
Joined
Oct 13, 2005
Messages
2,323
Reaction score
0
Location
plymouth,ma
the truck was built for what i do with it.i can show you the video where the damage was done.you can hear it go thru all gears and TC lockup,then ya hear it come out of OD and unlock the converter,then lockup again and hit OD.what i shoulda done was unplug my brake light switch when i got there.and i do drive it easy most of the time.stupid me wanted to go hang with the guys thanksgiving and roast some tires.with all the money i dumped into this truck this should not have happened.its not that i cant afford to fix it,its i dont have the cash on me to fix it.ive got around 15,000.00 owed to me for loans.but nobodies paying me cuz they dont have the money,ya i know stupid me once again.
 

94f450sd

certified nutjob
Joined
Oct 13, 2005
Messages
2,323
Reaction score
0
Location
plymouth,ma
well the tranny is definately junk.had about 1/2"of steel and aluminum shavings in the pan.time for a 5 speed most likely.
 

Members online

No members online now.

Forum statistics

Threads
30,506
Messages
266,043
Members
14,622
Latest member
rhensonsr
Top