# 700 r4 tranny problems again. Thinking of switching to a turbo 400



## daveolejnik (Jan 24, 2008)

I have a 92 chevy 2500 with a unimount plow. All I use it for it plowing and pulling trailers in the summer. I have had this transmission rebuilt at least 5 times now not including all the times I brought it in to be fixed. Reverse went out a few weeks back. I brought it back to the last guy who rebuilt it and of course my warenty was just up. He said he would give me a deal because off all the problems I have had. He tried saying it was driver abuse saying Im putting it in reverse before Im stoped. I know I never do that But I just went along with him because he pulled the trans and put new revers clutches in it and put it back in in a day and a half for $250. I picked it up new years eave, so it hasnt even been 3 weeks and less then 200 miles on it with very little plowing. 80 of the miles were driving it home from the shop. Well revers just went out in it again! I know I havnt put it in reverse to soon or abused it in any way. I am to the point Im ready to loose it. I was thinking about switching to a turbo 400 trans thinking it might be alot stronger of a transmission for plowing. I was told it should work but I need an adapter at the rear of it. What would you do if you were me? I havnt been able to get ahold of the trans. guy yet Im not sure if he is avoiding me or not. But I dont have much money being that Im disabled and Ive already spent a fortion on this truck. Im beginning to wonder if he just threw some used clutches in it that he had lying aroud his shop to get it done. Im no transmission expert but I should get more then 200 miles out of a trans. My problem is he just fixed it he didnt rebuid the hole tring again so I dont know if he will cover this. Any sugestion????????????


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## augerandblade (Jan 17, 2009)

Its possibly the reverese band that keeps on going there is a upgrade to the stock one. Ihad a 92 and 93 Chevy 6.5 Diesel 3.42 diff too much torque and too high gears. Switched to a 98 Chev 2500 with 350 gas and 3.73 gears only had too replace tranny wise a new upgraded band been plowing with the same clutch pack since day one


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## aeronutt (Sep 24, 2008)

700R4 transmissions are not strong enough for the abuse you put it through. The good news is the aftermarket has fixed every weak point. If you are getting stock rebuilds you will continue to kill them. Spend the money once (yes, it's a LOT of money :crying: ) to get a heavy duty upgraded transmission and then spend the money (yes, lots) to put synthetic ATF in it. I know a guy who owns a transmission shop and he claims to have had exactly zero failures on any transmissions that were treated to this combination. To hear him brag, you'd swear that synthetic ATF is the answer to all mans problems.

I would recommend getting a complete replacement heavy-duty rebuilt tranny rather than continuing to fix the one you have now. Check E-Bay for a guy in Florida that builds race & off-road trannies. They build 'em indestructable.

If you swap to a TH400 you will loose that wonderful low first gear that works great for plowing snow. You also need a different (probably custom built) crossmember and custom length driveshafts. The transmission to t-case adapter is different too. I think you'd be money ahead in the long run with the extra tough 700r4 over the TH-400.


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## NICHOLS LANDSCA (Sep 15, 2007)

It's hard to justify spending 2X as much on a HD 700r4 but you will have just as much into a 400 swap. And find a different tranny shop.


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## daveolejnik (Jan 24, 2008)

I was told the turbo 350 and 400 trans. will bolt right in. They are shorter and have a differand spline count. But there is an adapter you have to add to the rear off it so it will work. My friend owns a auto repair shop and he put a 350 trans in his. He know a transmission guy who will rebuild it an add the adapter for $200. that just seems to cheap. Thats iff you drop the trans. off there and you put it in yourself, and I m sure there no warenty. But my friend had the guy go throu his and he has been plowing all year without any problems. Does anyone know for sure if this guy is right about the turbo 350 working with an adapter?? Also how much does a rebuild kit cost for a turbo 350. Can this guy really rebuild it that cheap? Im guessing he just puts new clutches in it and looks everything over for that price. unfortionatly the guy who originally rebuilt my trans wont even return my calls. He was the one with the 400 trans also. I might have to go with a 350 turbo instead. I just want to make sure it will work with the adapter before I do it. I really dont want to replace it myself. But Im in a bind right now and tight for money. Ive spent a fortion on the 700r4 trans and Got ripped off BIG TIME, and now he wont even return my calls. Does anyone know for sure if the 350 turbo will work with this adapter???


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## exmark1 (Nov 30, 2005)

daveolejnik;721761 said:


> I was told the turbo 350 and 400 trans. will bolt right in. They are shorter and have a differand spline count. But there is an adapter you have to add to the rear off it so it will work. My friend owns a auto repair shop and he put a 350 trans in his. He know a transmission guy who will rebuild it an add the adapter for $200. that just seems to cheap. Thats iff you drop the trans. off there and you put it in yourself, and I m sure there no warenty. But my friend had the guy go throu his and he has been plowing all year without any problems. Does anyone know for sure if this guy is right about the turbo 350 working with an adapter?? Also how much does a rebuild kit cost for a turbo 350. Can this guy really rebuild it that cheap? Im guessing he just puts new clutches in it and looks everything over for that price. unfortionatly the guy who originally rebuilt my trans wont even return my calls. He was the one with the 400 trans also. I might have to go with a 350 turbo instead. I just want to make sure it will work with the adapter before I do it. I really dont want to replace it myself. But Im in a bind right now and tight for money. Ive spent a fortion on the 700r4 trans and Got ripped off BIG TIME, and now he wont even return my calls. Does anyone know for sure if the 350 turbo will work with this adapter???


I would go show up at his shop and talk face to face with him! Maybe you can resolve something that way...


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## russ130 (Oct 29, 2002)

according to Advance Adaptors you can not only switch to a 400 but also a 4L80E. Which is a 400 with overdrive basically.


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## BigDave12768 (Nov 17, 2006)

Not sure about the 400 But I changed my 700r4 in a blazer over to a turbo 350. Turbo 350 are tough as nails also. Tons of 350 trannys on EBay.

http://cgi.ebay.com/ebaymotors/chevy-turbo-350-to-np205-adapter_W0QQitemZ180321583330QQihZ008QQcategoryZ33727QQssPageNameZWDVWQQrdZ1QQcmdZViewItem


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## BigDave12768 (Nov 17, 2006)

daveolejnik;721761 said:


> I was told the turbo 350 and 400 trans. will bolt right in. They are shorter and have a differand spline count. But there is an adapter you have to add to the rear off it so it will work. My friend owns a auto repair shop and he put a 350 trans in his. He know a transmission guy who will rebuild it an add the adapter for $200. that just seems to cheap. Thats iff you drop the trans. off there and you put it in yourself, and I m sure there no warenty. But my friend had the guy go throu his and he has been plowing all year without any problems. Does anyone know for sure if this guy is right about the turbo 350 working with an adapter?? Also how much does a rebuild kit cost for a turbo 350. Can this guy really rebuild it that cheap? Im guessing he just puts new clutches in it and looks everything over for that price. unfortionatly the guy who originally rebuilt my trans wont even return my calls. He was the one with the 400 trans also. I might have to go with a 350 turbo instead. I just want to make sure it will work with the adapter before I do it. I really dont want to replace it myself. But Im in a bind right now and tight for money. Ive spent a fortion on the 700r4 trans and Got ripped off BIG TIME, and now he wont even return my calls. Does anyone know for sure if the 350 turbo will work with this adapter???


Chevy Turbo 350 are simple to rebuild. Rebuild Kit is about 50 bucks. I know I can rebuild one in about 5-6 hours and I suck at it. My friend can do it in about 2-3 hours and thats yapping away on phone while doing it. The cleaning of parts and stuff takes up most of the time. Keep in mind 200 doesnt include a TC. If you get a bone yard one get a new TC


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## russ130 (Oct 29, 2002)

400's are just as easy to rebuild as a 350 and cost roughly the same. It will be harder to find a 400 than a 350 but the 400 is way stronger and more reliable than the 350. You are still going to need a new rear shaft, front shaft and crossmember with either one since they are shorter than the 700r4 and if I remember correctly with a 400 you will need a new t-case or an adapter cause the spline count is different. If you need an adapter I think that will negate the shafts and crossmember though. I'm just going off the top of my head from what I recall a few years back when I contemplated a swap similiar to this. I was actually looking to go from a 350 to a 700r4 so I could have overdrive and save some gas on the highway. The 400 output shaft is larger and I believe 30 spline while the 350 and 700r4 are 27 spline if my memory serves. I'm getting older so my memory may be off so check into these facts before making any decision.


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## BigDave12768 (Nov 17, 2006)

russ130;723321 said:


> 400's are just as easy to rebuild as a 350 and cost roughly the same. It will be harder to find a 400 than a 350 but the 400 is way stronger and more reliable than the 350. You are still going to need a new rear shaft, front shaft and crossmember with either one since they are shorter than the 700r4 and if I remember correctly with a 400 you will need a new t-case or an adapter cause the spline count is different. If you need an adapter I think that will negate the shafts and crossmember though. I'm just going off the top of my head from what I recall a few years back when I contemplated a swap similiar to this. I was actually looking to go from a 350 to a 700r4 so I could have overdrive and save some gas on the highway. The 400 output shaft is larger and I believe 30 spline while the 350 and 700r4 are 27 spline if my memory serves. I'm getting older so my memory may be off so check into these facts before making any decision.


This is all wrong. Driveshafts are fine since they come off the transfer case not you tranny. Thats why you need adapter off turbo 350. The turbo 400 is not more reliable than a 350 either. They are just a bit stronger. But you can easily get a turbo 350 to hold up to 600 horse. The 350 is a simple swap


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## russ130 (Oct 29, 2002)

BigDave12768;723500 said:


> This is all wrong. Driveshafts are fine since they come off the transfer case not you tranny. Thats why you need adapter off turbo 350. The turbo 400 is not more reliable than a 350 either. They are just a bit stronger. But you can easily get a turbo 350 to hold up to 600 horse. The 350 is a simple swap


Before you go saying something is wrong maybe you should think it over a minute. Yes the driveshafts come off the transfer case. And the T-case is off the what? Oh hold on that would be the tranny right? But since the shafts come off the t-case even though the tranny is shorter makes no difference right? Hmmmm explain this to us please! I also seem to recall that you can't swap the adapters between 400 and anything. As far as the 350 vs 400 you have no clue what you are talking about, a bit stronger please. The stock version is 25% stronger which is more than just a bit but when you get to the aftermarket a 350 don't even compare to a 400. I've seen 400's built to handle in excess of 1200hp, twice the capability is a lot more than a bit. Now with all that said and the 400 obviously being far superior to a 350 the swap is going to be more involved than a 350 but may be worth it to some. For me it wasn't so I am personally running a 350 which has given me no problems to date. The only thing I wish I didn't do was install a towing converter cause it seems to have too low of a stall speed robbing the bottom end grunt. Also the 350 and 700r4 have different length shafts which means you have to grind one down and sorry I remember which one. Just measure where the tailpiece would go on, to the end of the shaft if the 350 is longer then grind it down if the 700r4 is longer don't worry its not much.


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## BigDave12768 (Nov 17, 2006)

700r4's are about 3 inches longer than a turbo350. If you look at my post above I linked the adapter for swap. As for the 350 and 400 being stronger. Its all in how you build them and want to spend.


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## russ130 (Oct 29, 2002)

That adapter is not going to work. It is missing the shaft that goes from the adapter to the t-case. Also the difference between that adapter and any adapter for a 350 is not going to be in the neighborhood of 3".

Now Dave what is wrong with you? *As for the 350 and 400 being stronger. Its all in how you build them and want to spend.* For someone saying I was all wrong you sure can't admit when you are. This statement of yours I'm gonna leave alone cuz its just too damn easy to tear apart and spit out.

Now Dave again to change subjects do you have any pics of that patriot plow? I'm a Pats fan too and would love to see it if it has cool graphics on it. In fact you just gave me a great idea, this summer when I am reconditioning my blade I'm going to paint it pats blue, red and silver and get a Pats logo sticker and put it on it then clearcoat over it about 3 coats.


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## BigDave12768 (Nov 17, 2006)

I did it on my 86 blazer Becuase the older 700r4 were weak being they had tons of plastic parts in them. As for the Patriots plow. It was Fisher made and you can buy the sticker from them Here is the ad for it. I will post mine later. My xgirl who I am still good friends with is a tattoo artist. plus an excellent free hand artist. I may have her paint my xblade with a Pats symbol on it. Just not sure yet what paint would work best and stand up to the abuse. A guy in my area runs a myer with Homer simpson painted on it. With Mr plow across top


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## CAT 245ME (Sep 10, 2006)

Back in the 80's when GM came out with the 700r4, the tranny's had alot of problems and it was very common for tranny shops to swap in a TH350 inplace of the 700r4. In order to do this there was an adapter that went between the tranny and T case. The adapter is only 1 3/4 inches wide.

I've owned 2 trucks an 85 & 86 K10's that had this swap done when I purchased them, but last winter the TH350 went in the 85 K10 so we swapped in a 700r4 from a 91 truck that a friend had so I could finish out the winter plowing with the truck. This winter the truck is a backup but when spring arives the 700r4 will be coming out in favour of a TH350 or TH400, it all depends if I can find a TH400 or not. These two tranny's are far better than the 700r4.

Which ever you decide to with get a large tranny cooler for it to.


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## Tomtsled (Feb 4, 2007)

Check one of these out:

http://www.700raptor.com


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