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Discussion Starter · #1 ·
My tranny is starting to slip O/D a bit and shifts pretty rough into O/D. The rest of the gears feel great and she shifts really nice and hard through acceleration, but that last slide into overdrive is just flat out rough 85% or so of the time.

Anyone had this happen or have any ideas on what to do?

105,768 miles on the car, motor, and tranny.

Keep in mind I have very limited funds so let me know what you guys think is the best plan of action on very little money.
 

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best place to start is to change the fluid.

when you change it make shure to drain the converter as well.

do not go to the quick lube place for this, make shure you either do it yourself or who ever does it manually removes the pan, changes the filter & drains the converter.
 

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Have it flushed not drained.

Though if its already slipping its already to late

if you havnt had it flushed before then shes pretty much ****ed
 

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Have it flushed not drained.

Though if its already slipping its already to late

if you havnt had it flushed before then shes pretty much ****ed
just flushing a trans does nothing because the main problem for trans function is a dirty filter.

once the trans is drained properly & the filter is changed then the only fluid left is the residual in the cooler & lines.
 

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Best case scenario is to drain the old fluid, replace the filter and follow it up with a flush, but that requires the use of a lot more fluid. And at roughly $5 a quart, most people go the cheaper route. Most of the time, slipping in 4th is caused by either a worn OD band, or wear in the OD servo pin bore causing less pressure applied on the OD band and excessive wear. You can try the trans fluid/flush/filter route which is the first step in most automatic transmission drivability issues with high miles on them, but my money says your OD band is shot. It is a pretty common failure on these transmissions.
 

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Best case scenario is to drain the old fluid, replace the filter and follow it up with a flush, but that requires the use of a lot more fluid. And at roughly $5 a quart, most people go the cheaper route. Most of the time, slipping in 4th is caused by either a worn OD band, or wear in the OD servo pin bore causing less pressure applied on the OD band and excessive wear. You can try the trans fluid/flush/filter route which is the first step in most automatic transmission drivability issues with high miles on them, but my money says your OD band is shot. It is a pretty common failure on these transmissions.
Does that require a rebuild?
 

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Does that require a rebuild?

No rebuild required, but it will require pulling the trans apart a little bit.

There is a small list of internal parts that can be used as upgraded replacements that can be used to ensure this doesn't happen again. Since the valve body needs to come off and everything, it will be the perfect time to do a shift kit as well if you have been considering that.
 

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Discussion Starter · #10 ·
best place to start is to change the fluid.

when you change it make shure to drain the converter as well.

do not go to the quick lube place for this, make shure you either do it yourself or who ever does it manually removes the pan, changes the filter & drains the converter.
No rebuild required, but it will require pulling the trans apart a little bit.

There is a small list of internal parts that can be used as upgraded replacements that can be used to ensure this doesn't happen again. Since the valve body needs to come off and everything, it will be the perfect time to do a shift kit as well if you have been considering that.
Are there write-ups on either of these or can you guys give me a quick run down on the tools and equipment and knowledge needed for these two things?

I'll be honest...I know engines and I know paint...I'm clueless about most transmissions. I know their basic internal parts and functions, but as far as working on them I have zero experience.
 

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Discussion Starter · #12 ·
I have a guy offering to sell me his 40k mile TR-3650 right now. It includes his Steeda Tri-As shifter, driveshaft, bellhousing, and cross member for $700

I don't exactly have $700, but it's definitely an option I'm considering.

If I went to a Manual, I'd rather go with a T56. However, this deal on the 3650 sounds pretty good.

What would it cost me to perform the necessary repairs on my 4R70W if I did the work myself, and it is something I could learn to do quickly so that my car isn't off the road for a long time?
 

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IMHO if you go from a 4r70w to a t45/t3650/or 10spline t56 your going backwards esp if you want power later on.
 

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Be sure it's actually an OD band problem before you spend the money. I've seen waaaaaay too many 4R70W's over the years that showed signs of slipping going into OD. When I test drove them, that wasn't the case at all. When it shifted from 3rd to OD, it would feel like you were running over those warning strips on the road until the gear change was complete.

If that's what yours is doing, then the chances of OD being bad go down, and the chances that your torque converter showing signs of wear goes up. I'm not saying that the OD band isn't bad, but 7 out of 10 times someone thought they had an OD problem, it was actually a converter problem in the 4R70W's. Sometimes a complete change of fluid with some fresh MERCON V, including draining the converter fixed the problem, sometimes it didn't, and the converter had to be replaced, but I'd definitely start with a complete fluid change. I remember it being 13 or 14 quarts to totally refill the transmission and converter. It's somewhere around there, but I can't remember for sure right now, it's been a few years since I had to turn wrenches on other people's cars.
 

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These two links give a quick run down of the "common" 4r70w issues and how to diagnose them just FYI. Your rough 4th gear shift means a couple things. Again, I would start by changing the fluid and filter. When you get the pan open, you will be able to see if there is excessive amounts of friction material in the bottom of the pan and shavings stuck to the magnet.

TCCoA Transmission Article - Page 4
TCCoA Transmission Article - Page 15

If you need to go into the trans and replace the OD band, we are talking about a $30 in parts, about $15-20 worth of seals/gaskets, and another $75 worth of fluid. You are going to need a good set of tools, the ability to pull the transmission, and some sort of fixture that will enable you to mount or place the transmission with the bell housing facing upwards for you to install the parts and do the work. An engine stand will work just fine, but some prefer an actual transmission holding fixture. Only specialty items to be noted are a decent set of snap ring pliers, a slide will hammer help in removing the pump (but not required), thread sealer, in/lb torque wrench, hook and pick set, a slide caliper with the ability to read depth, a small straight edge with a hole drilled to accommodate the depth portion of the slide caliper, and that's about it. Might sound like a lot, but really that is just the bare essentials.

Long story short, you need to get the trans out and mounted bellhousing facing up. Pull the pump. Pull the valve body. Pull the OD servo piston and pin. Pull the intermediate clutch along with the reverse drum. Replace the OD band, and re-assemble in reverse order. I would also replace the OD servo pin with the upgraded sonnax kit that has 2 o-rings while you are in there.

There are a lot of good videos on the assembly of the 4r70w and the AOD/E, but nothing that really covers this install. I might put one up shortly, but it probably won't help much in your case since you have the problem now.
 
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