700r4 problems

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Johnathan S

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so my truck originally came with a 700r4 and it’s pretty tired shifting from each gear takes a little longer than it should. So I searched for a cheap one can across a company named AT Racing World on eBay that sold them fairly cheap now I know that was my big mistake was buying a transmission off eBay but I’m in high school and got what money I could to just get something that was decent. Me and my dad installed it in one day and it was fine for the first 4-5 days and then In the mornings it would take a little driving for the trans to stop slipping. And not slipping going form gear to gear just slipping from a dead stop. so say I reverse out of my driveway and put it into drive, it slips bad but eventually smooths out and as it warms up it gets better and I don’t experience any problems until I let it sit for awhile again and it does the same thing. Also reverse is really weak it’s not like my old one where when you shift it jerks the truck and it’s immediate with this one you put into reverse and get on the gas until it actually starts moving. It’s full on fluid and also when I got this transmission I got a new torque converter with stock stall that the truck would’ve came with. I don’t know what the problem is figured I’d get on here and maybe find an answer... probably just get a new transmission that’s new and not rebuilt
 

HotRodPC

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So if your shifts were tired in the first transmission, but it wasn't slipping, that sounds to me like it needed a TV cable adjustment to firm up the shifts and bring the line pressure up because that's what the TV valve does. It regulates fluid pressure and if the shift was tired that's maybe all it was.

As far as the new transmission, it sounds like you got fuct. Many builders don't go into the detail that needs to be gone into on 700r4's on the valve bodies. 700r4's are well known for wearing vavle bores in the valve body. If you don't have the tools to check the valve bores or at least the common ones, then they get over looked and you get line pressure bleeds and leaks. That's going to be my GUESS and it's just that, a GUESS. I'd say it could have be a seal installed wrong but you said it worked for a few days and also from your description, it's not just one or 2 gears it's all of them, so I'm going with bad vavle body. However, just for ***** and giggles, do an adjustment on your TV cable and make sure that is correct. If that don't fix it, then I'll go with my first guess. If that's the case, you may be able to swap the valve body out of your old transmission and have it work since it doesn't sound like you really needed a transmission just yet.
 

HotRodPC

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But hey, let me back up on something I suggested and here's why. 700r4's were not reliable for many years. So there were changes and fixes every single solitary year and even sometimes mid year. Because of all these changes, many parts ARE NOT compatible with every year model. Like a Turbo 350 or 400, most all parts are interchangable and it doesn't make a **** what you put with what, but in a 700r4, that's just not true. Sooooo, unless you know what year model transmission you pulled out and what year model you installed, and if they're compatible with each other, don't swap those valve bodies. I'd sure email the seller of that transmission on eBay though and see what he suggests. Was it a used transmission or a rebuilt?
 

Kim Burke

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Have you rechecked the TV(throttle valve) cable adjustment. These trannies(700R4) will not last long if the cable is not adjusted correctly. I had a brand new cable that didn’t completely click into adjustment and readjusted with quick shifts and no kick-down passing gear after I went full throttle.
I would think there is someone you could call from this rebuilder to give you a hand. I was blessed to find a great rebuilder that diagnosed the problem before permanent damage. Good luck
 

1987 GMC Jimmy

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I agree with HRPC. Not only should you have checked your TV cable adjustment, but a Transgo kit would have helped with that mushy feeling. I hate to sound like an armchair critic, and everyone learns hard lessons when it comes to vehicles, but you shouldn’t ever give up on a transmission until you know for a fact that it’s toast. I have one that has 184K miles, and it shifted absolutely atrociously. Bad. I thought the trans was fried, but the governor was bad, I put a shift kit in it, and boom. Shifts like a brand new transmission. My other 700 has 273K miles with no rebuild and shows no signs of slowing down. I’d take it up with the builder, I don’t know what kind of guarantee they have, and if they stonewall you, go to the BBB and review sites and complain. Companies like Monster will send you a back a no good transmission time after time after time, but luckily it isn’t them so maybe you can navigate your situation with better success.
 

HotRodPC

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I agree with HRPC. Not only should you have checked your TV cable adjustment, but a Transgo kit would have helped with that mushy feeling. I hate to sound like an armchair critic, and everyone learns hard lessons when it comes to vehicles, but you shouldn’t ever give up on a transmission until you know for a fact that it’s toast. I have one that has 184K miles, and it shifted absolutely atrociously. Bad. I thought the trans was fried, but the governor was bad, I put a shift kit in it, and boom. Shifts like a brand new transmission. My other 700 has 273K miles with no rebuild and shows no signs of slowing down. I’d take it up with the builder, I don’t know what kind of guarantee they have, and if they stonewall you, go to the BBB and review sites and complain. Companies like Monster will send you a back a no good transmission time after time after time, but luckily it isn’t them so maybe you can navigate your situation with better success.


Solid Advice here. It's not being an armchair QB to say about learning those hard lessons. But there are 2 different types of people who work on their vehicles. There's parts changers and there's mechanics. What you did @Johnathan S was played parts changer of a major part for what could be a minor problem. I realize you're new here, but what we try to do here is diagnose a problem first. Then replace what needs replacing. Don't go spending money and time guessing. Sometimes it does require to change out a part and if it's not that, when know for certain it's this, but we'll sure start with the cheapest easiest possible solution first or something that can be considered needed maintenance anyway. Like if you're not getting fuel, and haven't changed the fuel filter in moons, let's take 10 minutes and $8 to replace that fuel filter FIRST before we assume it's the $200 in tank fuel pump when the filter was due to be replaced anyway, and hope that corrects the problem. If not, well so be it, it needed the filter anyway and it wasn't a waste.

So next time, come here first, give the best description of the problem you can in detail, post pics too if it matters and let us help you diagnose something. There isn't a damn one of us here that knows everything, but between all of us, we damn sure do know everything. Almost 17,000 heads are better than one. Don't be afraid to ask stupid questions. Some forums belittle people for stupid questions, but it's not tolerated here. Never has, never will. It has happened before and we shut that **** down. So it's a hard lesson but now you know. Come here first next time.
 

The88

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Yeah what they said and welcome.
 

Johnathan S

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Solid Advice here. It's not being an armchair QB to say about learning those hard lessons. But there are 2 different types of people who work on their vehicles. There's parts changers and there's mechanics. What you did @Johnathan S was played parts changer of a major part for what could be a minor problem. I realize you're new here, but what we try to do here is diagnose a problem first. Then replace what needs replacing. Don't go spending money and time guessing. Sometimes it does require to change out a part and if it's not that, when know for certain it's this, but we'll sure start with the cheapest easiest possible solution first or something that can be considered needed maintenance anyway. Like if you're not getting fuel, and haven't changed the fuel filter in moons, let's take 10 minutes and $8 to replace that fuel filter FIRST before we assume it's the $200 in tank fuel pump when the filter was due to be replaced anyway, and hope that corrects the problem. If not, well so be it, it needed the filter anyway and it wasn't a waste.

So next time, come here first, give the best description of the problem you can in detail, post pics too if it matters and let us help you diagnose something. There isn't a damn one of us here that knows everything, but between all of us, we damn sure do know everything. Almost 17,000 heads are better than one. Don't be afraid to ask stupid questions. Some forums belittle people for stupid questions, but it's not tolerated here. Never has, never will. It has happened before and we shut that **** down. So it's a hard lesson but now you know. Come here first next time.
It’s a hard lesson I learned not trust eBay lol but my other transmission was on its last leg I could tell and the cost to rebuild it was the same to buy a rebuilt one so that’s what I did. I don’t know about internals of a transmission I did an engine swap and in the process took the trans apart to check it out... could not for the life of me find the right filter tried 4 kits non of them were right, so I threw the 30 something year old filter back in and called it good (something I wish I didn’t have to do) not only that but the pump seal went out, every time I larked there was a puddle. and I told myself the only way that transmission is coming out is if a new one is going in. Idk how easy it is for everyone but this truck is my daily driver everyday to and from work and school. so that all being said I don’t exactly know what I was supposed to troubleshoot there, it was an old trans, I bought a rebuilt one and put it in. I’m not one of those people that just replaces anything that’s broken with something new, I’m in high school... I’m broke as hell. It’s one of those things where you gotta say welp is it better to just spend the money and replace it or spend however long trying to fix something that might not even get fixed
 

Johnathan S

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But hey, let me back up on something I suggested and here's why. 700r4's were not reliable for many years. So there were changes and fixes every single solitary year and even sometimes mid year. Because of all these changes, many parts ARE NOT compatible with every year model. Like a Turbo 350 or 400, most all parts are interchangable and it doesn't make a **** what you put with what, but in a 700r4, that's just not true. Sooooo, unless you know what year model transmission you pulled out and what year model you installed, and if they're compatible with each other, don't swap those valve bodies. I'd sure email the seller of that transmission on eBay though and see what he suggests. Was it a used transmission or a rebuilt?
Rebuilt
 

HotRodPC

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Yeah, I'd hit up the seller then and ask what they want you to do. Did you pay by paypal? How long ago? eBay and PayPal have policies. If you didn't get something as advertised, they'll refund you money. It may require you to ship it with tracking back to the seller though. When tracking shows delivered, they'll refund your money. Seller most of the time don't have a choice.
 

Johnathan S

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Yeah, I'd hit up the seller then and ask what they want you to do. Did you pay by paypal? How long ago? eBay and PayPal have policies. If you didn't get something as advertised, they'll refund you money. It may require you to ship it with tracking back to the seller though. When tracking shows delivered, they'll refund your money. Seller most of the time don't have a choice.
Problem found, somehow my trans fluid disappeared, I got some of that Lucas oil stop slip and put a little in and I know transmission additives aren’t usually good to use but I figured what the hell. My guess is a valve was stuck or a passageway or something but got home pulled the dipstick out and no fluid was showing and this was on a level surface with engine and trans warmed up and in park running
 

HotRodPC

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Any sign of the fluid under the truck? Is it losing it out the breather tube? It went somewhere and you're going to have find out where it went.
 

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