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My trans pan is leaking some so I am going to be replacing it soon. While I am at it, I want to ensure I am replacing the filter. I have a 76 with the L48 mated to the THM350 Auto Trans. I am having trouble finding the right gasket and filter kit. I don't have experience with this, so I really don't know what is the right product. Should I buy the gasket and the filter separate?
That's the right one for a TH350. That kit has the filter, filter to valve body gasket and the pan gasket. That pan gasket appears to be a rubber one, not my first choice but it's functional. Just be careful with the bolts when you install the pan.
After you take the pan down and clean the gasket surface, check the bolt holes in the pan flange to make sure they are flat. Overtorquing the bolts will deformed the flange, making it harder for the gasket to seal. A small hammer can flatten the flange back to normal.
look for a cork & neoprene pan gasket...they seal best...put on dry, no sealer. torque all pan bolts to 8ft lbs then all to 12 ft lbs. come back in a week and retorque to 12. you'll need 4+ quarts of fluid
Try NAPA as that filter kit you show is cheap crap...that gasket sux....rubber and the black paper ones they sell do not seal as well as the cork & neoprene composite. As stated, flatten pan rail if needed...NO SEALER!!!
Last edited by jimvette999; 08-28-2017 at 08:04 PM.
Honestly the gasket isn't really my concern, as I will be buying a fel-pro rather I was looking at that kit due to it coming with the trans filter. I can't find another kit like it. Does the filter piece not need to be messed with?
Honestly the gasket isn't really my concern, as I will be buying a fel-pro rather I was looking at that kit due to it coming with the trans filter. I can't find another kit like it. Does the filter piece not need to be messed with?
You can buy the filter and filter gasket separate from the pan gasket without issue. There are different filter styles but they function similarly and will work no matter their design.
The:Purolator P221
is the black gasket.....not very good!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!
Looking at the pan and the old gasket, it looks like it has never been serviced or changed, or at least it has been a really long time. Any thought as to putting the old fluid back in? I have heard Lucas ATF conditioner works great with new fluid though. I just don't want to be part of the horror stories of transmission failure after fluid change.
You have to drain the trans to replace the filter- As long as the pan is not full of trash it should be OK. Trans fluid is not very expensive, and you'll still need new fluid to top it off.
how about FRAM FT1033B - for an 81? $4.68 @ rockauto
w/UltraCork Gasket
The FRAM Transmission Filter now features a cellulose gasket that has been redesigned with smaller gasket holes, making it easier for technicians to secure the bolts that keep the gasket in place and aiding in installation. The cellulose material also affords good recovery and compressibility to help provide an excellent seal.
Looking at the pan and the old gasket, it looks like it has never been serviced or changed, or at least it has been a really long time. Any thought as to putting the old fluid back in? I have heard Lucas ATF conditioner works great with new fluid though. I just don't want to be part of the horror stories of transmission failure after fluid change.
I know what you are talking about. Had that problem. If I have a car and the fluid hasn't been change I leave it. Just change the filter.
The only time I can imagine running into an issue with changing the fluid is if you have the transmission flushed which stirs up all the sediment sitting in the bottom of the pan. There is no reason to reuse old chemically broken down transmission fluid.
The only time I can imagine running into an issue with changing the fluid is if you have the transmission flushed which stirs up all the sediment sitting in the bottom of the pan. There is no reason to reuse old chemically broken down transmission fluid.
Researching this, there seems to be a lot of debate. Some say that over the years the sludge (for lack of a better word) that builds, provides good thicker lubrication as the parts in the trans slowly breaks down. Doing a flush knocks out the sludge and there is no longer that barrier so the trans is quick to break down. Some claim putting in new fluid also breaks loose that sludge/lubricant causing the same problem. Obviously a slightly leaky trans pan is 10x better than a non-leaky trans pan under a trans that is blown.
Here is the gasket I got
I think it is one that goes on dry without sealant. I also got some Lucas ATF conditioner.
08-27-2017, 02:09 PM
Correct Trans Pan Gasket and Filter
