# Transmission Rebuilding



## Daniel 89 Hardbody (Jan 12, 2015)

Is it possible to do a partial rebuild of my automatic transmission? I have a 89 SE-V6 4x4 with 200km on it. The transmission is getting very hot and shifting very hard. I like not to pull the entire transmission apart if I can help.


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## smj999smj (Jan 1, 2006)

It all depends what's wrong with it. There are limited services that can be performed on-vehicle, such as valve body replacement. To work on clutch drums and their parts, planetary gears, one-way clutches, bearings, etc., the transmission will need to be removed and taken apart. If the transmission is getting hot and/or the fluid is burnt, there may be an issue with the integral cooler inside the bottom tank of the radiator. It can be cleaned out to a degree with a product like Kooler Kleaner, but Nissan usually recommends replacing the radiator when repairing or replacing an automatic transmission to ensure a clogged or restricted cooler doesn't damage the new or rebuilt transmission. There are a number of tests listed in the service manual, along with a symptom chart, that can be helpful in diagnosing a transmission problem. It also shows what is serviceable without trans removal and would can be repaired in-vehicle.


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## Daniel 89 Hardbody (Jan 12, 2015)

I was thinking there maybe a cheaper way out with my transmission issue. Many thanks,


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## Daniel 89 Hardbody (Jan 12, 2015)

How can I tell which transmission I have? The manual has a 71B type and a RE4R01A type. The sun visor on the driver side that shows the directions for going in and out of 4 wheel drive has it as 41G17H.


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## SPEEDO (Jun 9, 2003)

should be the RE4R01A, the tags in the door jamb/firewall should confirm this


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## Oldnissanguy (Jan 6, 2005)

With 200KM and hard shifting, I'm not sure you can avoid a rebuild. However if you want to try something how about the following. 

Drain the transmission being sure to catch the fluid where you can inspect it for metal or other chunks of stuff. If it looks reasonable, drop the pan and inspect for more stuff. It's time for a rebuild if you find any material in either case. 

Replace the filter and reinstall the pan. Pull the inlet and outlet hoses off the transmission and flush through one hose, through the cooler and out the other hose. Use something like smj999smj suggests. Reattach the hoses once you get a clean flush and the flush has drained out. 

Fill with the correct transmission fluid and try it. If by some miracle it works acceptably, I would suggest adding a transmission cooler.


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## Daniel 89 Hardbody (Jan 12, 2015)

Thank you all. Speedo was right, the tag on the driver side door jam confirm the transmission is the RE4R01A. I am the original owner of the truck. It has never been hit. At around 30km I heard a high pitch noise coming from the transmission and I took it to the dealer. They replaced the tranny and the radiator. I have own this truck for 26years. Now I use it as my weekend going to the lumber yard truck. I like to keep it running as long as I can. I try doing the self diagnostic but the AUTO/POWER button would not stay in the AUTO position. Any good ideas. Also if I get a tranny cooler what size should I be looking for. If I get a separate cooler for the tranny I can replace the radiator with a manual shift version for the larger cooling capacity.

Many thanks,


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## smj999smj (Jan 1, 2006)

I would stick with the automatic transmission radiator; most aftermarkets don't give you a choice as they use the automatic style for both applications. The integral cooler of the radiator has the benefit in that it not only has the capability of cooling the ATF (liquid to liquid coolers are more efficient than air to liquid coolers), but it also serves to warm the transmission fluid to normal operating temperature. Ideally, ATF should operate in the 175-200 degrees F. range. If you repair or replace the transmission, you should clean the radiator cooler by flushing it with a product like Kooler Kleaner. There is a Nissan TSB on the procedure. It also gives information on how to determine if the radiator should be replaced rather than just flushed based on the flushing procedure results. Of course, if the radiator is the original part, it might just make more sense to replaced it, anyway, rather than bother with flushing the cooler.


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## Daniel 89 Hardbody (Jan 12, 2015)

Thanks smj999smj. I would be better off replacing the radiator since it is 24 years old with 170km of wear. I got my money's worth. Does any body know where I can buy the POWER/AUTO switch assembly for this automatic transmission shifter? Does anyone know the part number to this assembly?


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