89 F150 Transmission Fluid\Filter Change, tips?

[CanukGMC]

I bought an beater bush truck for 800$ the other day. It's an 89 lariat with the 302 and automatic. So far it's been a great truck however the shifting patterns are somewhat erratic or delayed and sometimes it shifts (especially downshifting) really hard. I checked the dipstick and sure enough it's looking burnt. So I'm going to put some seafoam transtune tranny flush in it then drain it and change the filter\fluid. Is there anything I should be aware of before I get in there? Does anyone know if I can buy a new gasket for the pan or do I need to use gasket maker? Thanks

[taillight]

No problem getting a gasket but change the filter also at the same time.

[CanukGMC]

Originally Posted by taillight

No problem getting a gasket but change the filter also at the same time.

Definitely, it'd be crazy\stupid not to. Also does anyone know what tranny and what type of fluid I need? My oh-so-usefull haynes manual just says "mercon" but doesn't say if it's mercon iii or mercon v. Anyone?

[taillight]

You can ID the trany by the bolt pattern. For a 98 Mercon 3 is fine.

[CanukGMC]

Ok wtf is going on with the fluid amount. My hayes manual (USELESS!) told me to add about 12-16 quarts of ATF to the tranny, if you convert that it's roughly 13 or 14 liters (we buy in liters here). That's practically 4 gallons of atf! SO I bought it all, <sigh>, and started filling the tranny. Luckily I checked after each liter (quart) and noted after only about 4 the tranny was not only full, but slightly overfull. 4 quarts is a FAR cry from the 12-16 that hayes told me. I drove around to make sure the torque converter and solenoids were all filled and used, my fluid still shows somewhat overfull so I'm going to have to find some way to put a tube down the dipstick hole and suck out from fluid (sounds fun). Anyone in the world know why the hayes manual would tell me roughly THREE times (300%!) the amount I actually needed??

[Torch]

Probably a mis-print or a conversion error.

To get the extra fluid out use a thin vacuum hose and the sprayer assembly from an empty bottle of Windex window cleaner, should pump it right out, just squirt it into a tin can or plastic bottle.

[mightymouse466]

Originally Posted by CanukGMC

Ok wtf is going on with the fluid amount. My hayes manual (USELESS!) told me to add about 12-16 quarts of ATF to the tranny, if you convert that it's roughly 13 or 14 liters (we buy in liters here). That's practically 4 gallons of atf! SO I bought it all, <sigh>, and started filling the tranny. Luckily I checked after each liter (quart) and noted after only about 4 the tranny was not only full, but slightly overfull. 4 quarts is a FAR cry from the 12-16 that hayes told me. I drove around to make sure the torque converter and solenoids were all filled and used, my fluid still shows somewhat overfull so I'm going to have to find some way to put a tube down the dipstick hole and suck out from fluid (sounds fun). Anyone in the world know why the hayes manual would tell me roughly THREE times (300%!) the amount I actually needed??

Actually your transmission DOES hold 12 - 16 quarts. But most of it is in your tranny cooler and other places inside your tranny that will not drain by dropping the pan and changing the filter. Doing a filter change you will only loose about 4 or 5 quarts. This is fine for regular maintenance, but if yours looks burnt you may want to consider taking it somewhere and having the tranny flushed. You could keep the price lower by taking your extra tranny fluid and having them use that.

[CanukGMC]

Originally Posted by mightymouse466

Actually your transmission DOES hold 12 - 16 quarts. But most of it is in your tranny cooler and other places inside your tranny that will not drain by dropping the pan and changing the filter. Doing a filter change you will only loose about 4 or 5 quarts. This is fine for regular maintenance, but if yours looks burnt you may want to consider taking it somewhere and having the tranny flushed. You could keep the price lower by taking your extra tranny fluid and having them use that.

Nah I'm not dropping anymore money in it than I need. It shifts alright right now, the fluid looks more red now that I swapped it and I've developed a leak either in the rear seal from OVERFILLING it or on the rear pan gasket due to a stripped bolt (thanks for the wrong torque spec hayes!). I'm just gonna leave it alone, top it up as it needs it and see how much I get out of it, it's still running\driving good so why spend more than I need. It's an 800$ truck I might add lol.