I babied my new 700-r4 for two years...and now I'm walking!

[Krazy_Eskimo]

I babied my new 700-r4 for two years...and now I\'m walking!

I've been an in and out barfly here at coloradok5 since it was just a listing of posts on a page. And I am amazed at how far it's come in the few years since! Congrats to Grim for taking charge and moving it along!

Anyways. Here's my sad, sad story and I hope you all can relate.

I bought a 1984 Chevy Blazer FS from a guy for 800 bucks just after Christmas 2 years ago. I had an 86 at the time and wanted to get something that already had the 6" lift kit and the 35's and all the works so I didn't have to go through the process again with my '86.
So I purchased this bad boy with the knowledge that it had a blown 700-r4 trans and it needed a rebuild. So I had the trans rebuilt with all the latest goodies that a 700 r4 could take to use on the trail for "mild" wheeling and also use it as a daily driver. I wanted to keep the 700 because of overdrive and I drove this thing to work sometimes from Maine to middle of Massachussetts.
Pretty soon after I got the truck back it started to make clunking noises from putting it in gear. But i was assured it was just the loosenes from the bearings inside the axle housings that needed to be replaced. I drove it this way for 20,000 miles until I replaced those.
I babied this trans and this truck. I loved driving it and the way I had it flexing on the trails It should have been in Petersons magazine at least half a dozen times the ways and things I had it doing.
Anyways, Last Saturday on my way down to New Hampsahire to see my girlfriend, I was really putting the trans through it's paces passing little rice burner SUVs like they were standing still and playing traffic tetris through the construction zones along i-95 south all the way down to the York Tolls in maine. Everything seemed ok until I pulled away from the tolls after about 100 yeards I got no forward gears. nothing! It was raining! Pouring... I managed to get it to move in first gear so I could get under the cover of a bridge so I could look underneath and inspect it for any leakage or things oput of alignment. There was no warning, nothing. It just didn't want to go forward until I put some gas to the pedal. I have no idea what has happened. If this had happened on one of my trail riding expeditions I would have been screwed but since it's been on the road for the last 3 months, and hasn't really seen any twisting or bump and grind wheeling I don't know what it is. I was tired and out of luck from then on... My cell phone had only one cube left and I had a desicsion to make... calll the girlfriend or call triple A and get a truck to help. The girlfriend would have been comforting but you know how it goes... I'd still be there and the phone would have been dead. God I love her.
So, I'm requesting some ideas here... Since the info from the SEARCH engine here is so scatterbrained all over the place with no real category to speak of... How about some 700-R4 tech tips on REBUILDING the 101 yourself!
I had it done and it lasted 2 years. I know that if I don't have any forward or reverse that it could be ALOT of things... I change this fluid at every 20,000 miles weather it needed it or not. Engine: 350 with Quadrajunk carb. If we know how to do this ourselves...it will get cheaper and easier with everytime we do it ... right?

If I don't make any sense or I don't have the right column I am sorry for posting here. I'm just used to the good 'ole days when You could post and see that other might have the same answers to your problems. I can handle the girlfriend..... she's not an issue... that fact remains that I don't have wheels to get to work and I can only hold off not getting there for a while. thank god for email.
Mean time I'm fixing my old motorcycle to get around town on... But I'd rather be wrapped in Chevy Blazer with my left arm resting out of the window and the great 2002 farmer tan to work on!

Keep on keeping on K5er's
We're all in this together!
-Drew

 

[Can Can]

Re: I babied my new 700-r4 for two years...and now I\'m walking!

Rebuilding a 700 PROPERLY is tricky. A lot of tranny shops can't manage to do it properly(which may be why you're truckless right now), so unless you're really mechanically inclined and have all the right tools, I wouldn't recommend trying to rebuild one yourself.

I'm far from a tranny guru, but there's a few things you can do to help your 700 last longer. First off, install a big stacked-plate auxilliary tranny cooler. Secondly(and it sounds like you've done it), make sure that your ATF is kept clean. ANd third, try to avoid driving around in OD unless you're on the highway.

FWIW, I have a rebuilt 700 in my 84. I had it done in 1992(with all the updates) and haven't had a tranny problem since. I tow through the mountains every summer but I also follow a strict maintenance schedule.

 

[Blazer1970]

Re: I babied my new 700-r4 for two years...and now I\'m walking!

If it would do nothing but creep forward when you give it gas, it is most likely the lockup torque converter that took a crap. Unfortunately, that usually spreads metal chips throughout the tranny, necessitating a rebuild anyway. If you do rebuild the tranny again, make sure that you buy a quality torque converter.

 

[Krazy_Eskimo]

Re: I babied my new 700-r4 for two years...and now I\'m walking!

If I remember correctly, weather or not this actually makes a difference, the people at Northeast Trans said it was a "non-lock up" torque converter. And yes, he bought the good torque converter/ not a re manufactured one.

I had run two trans cooloers along the inside channels of the frame rails to cool it down ...since that was suggested to do so after the install.(it was cooled thru radiator as well.

I don't understand it. probably never will. I guess I should have kept the old Standard blazer trans. I don't think I'm going to go back to automatics ever again.

What a pain in the A!

 

[transcore1]

Re: I babied my new 700-r4 for two years...and now I\'m walking!

Hey Krazy, I've been there. There are a few things you can do next time when doing the rebuild that could help. First, look for a later core. Look for an 87 up core that has a rainbow shaped stripe in the aluminum casting around the servo. This is what is known as an "auxiliary" type or "auxiliary valve body type". They have updated this tranny at least 6 times and yours is first gen. Now on the DIY idea, think about the blood sweat and tears it takes to get it in and out before you try it. The R&R is definitely the hard part. Without a lift and a trans jack it is an all dayer. Now think that in DIY mode you could have to do this several times. OUCH!!!! Your best bet would be to find a good, local, independent shop. Check with the Better Biz Bureau, get refs., ETC. Now when you decide, let's talk about what you want. In my opinion you should insist on all NEW bushings,steels,clutches,and bearings in addition to the standard overhaul kit. Worn bushings allow internal movement that accellerates wear. Worn steels don't "grab" when engaged and slippage causes heat which breaks down fluid and grenades everything. Used bearings can fail because of almost microscopic pitting that causes the needles to wobble out of their keepers and grenade. Overheated clutches can warp and cause the same slippage problems as the steels. When choosing clutches, I prefer "Blue Plate" by Raybestos. We have used them in high horespower apps. and they hold up better than any. It ia also not a bad idea to change the sprag elements while inside. The mods listed here will add around $300 to a rebuild but you won't have to do it again so soon if it is done properly.
To save money maybe you should have the unit "benched" that is you pull it and have it built, then reinstall it. Don't forget to flush the cooler or replace it completely and flush the lines. THIS IS A TRANS KILLER. A dirty cooler can grenade a brand new tranny.

Hope this helps.
Transcore1 Check out our Blazer project under ABOUT US

 

[Blue85]

Re: I babied my new 700-r4 for two years...and now I\'m walking!

My first time in my garage took 4 full days. 2 of those were pretty much pulling the slushbox and putting it back in. You have to pull driveshafts, crossmember, Transfer case, support rods and maybe exhaust before you can even get to the tranny. Plus there are lines, wiring, linkages, etc. You have to have a transmission jack. My best time is 6 hours to pull the tranny in my garage. After you do one, you understand why it's so bleeding expensive.

Just be sure that you're mentally prepared to endure the agony of 4 days of dirt, oil, grime and careful concentration DOWN THE DRAIN because one of many dozens of things was not done just right. You might get lucky like I did, but you might be back to square one.

I recommend finding a shop with a transmission dyno. Then if you pull and replace, letting the shop do the rebuild, at least you know that it's a working unit going in. If you do the rebuild yourself, again, you can find any trouble without going through the install/uninstall process again.

The auto tranny is the most complicated device in your vehicle, but it is only a machine. If it is assembled as it was intended, it will function as it was intended. But there are a lot of variables and subtle things that are not obvious without experience. It's easier to get a stock rebuild right then to do a ton of mods on your first rebuild. I did that and ending up going back and forth between two different manuals and reading between the lines and making up my own stuff that they didn't cover. Risky.

You might want to just price out a rebuild from a shop with a good name and just use a weekend to trade it out. They're not always very expensive and they may give a warranty.

Good luck to you, I hope it turns out OK.

 

[DieselDan]

Re: I babied my new 700-r4 for two years...and now I\'m walking!

Boy doesn't this sound familiar. My '89 is making terrible rattling noises sometimes. Sometimes it doesn't want to shift (at all). I knew this tranny was shaky when I bought the truck; it was someone's half-assed rebuild.

I'ld really like to swap in a NV4500 but I don't think I canfund the down time (especially if my 700 craps out unexpectedly). I could drop in a 400 I got, but I really need the OD (4.56 and 6.2). Bowtie has a built 700 for about a grand. Iv'e rebuilt a TH350 years ago so I think I could handle a 700 if I don't need much for specialized tools. But I have to ask myself how much cash I can save rebuilding (with all the GOOD parts) vs. buy outright BUILT w/WARRANTY. Damn, I wish I could trip over a NV4500 walking to my truck tomorrow morning /forums/images/icons/grin.gif

Much closer 'skmo, and we could carpool /forums/images/icons/smirk.gif

 

[Krazy_Eskimo]

Re: I babied my new 700-r4 for two years...and now I\'m walking!

Just a thought. What about pulling the 700 and finding a Standard shift Donor truck. Could I ostensibly slide in the standard trans provided the bolts all line up.. is there a spacer kit that I'd need if I stayed with the NP 208(which I just rebuilt!)

I'm almost ready to give up and sell it. Anyone want this beast get back to me. If you're in the New England area and have some time. Come and take a look. It's nice. but won't be for long.

-Krazy_eskimo

 

[Oblin Goblin]

Re: I babied my new 700-r4 for two years...and now I\'m walking!

I had almost the exact same thing happen to me. Almost exactly 2 years after I had my 700r4 rebuilt the converter seized up on me. Aamco said they would help me out on the bill since it was only 2 years but they couldn't tell me how much. I figured they'd credit me like $50 or somthing and them make exusese as to why they could cover me for any more than that. In the end I blew them off and installed an nv4500 /forums/images/icons/smile.gif. If i were you I'd look into a Jet Performance 700r4. The nv4500 is really cool now that its in there but was it was mighty expensive.

 

[m j]

Re: I babied my new 700-r4 for two years...and now I\'m walking!

no more $$$ then a Jet 700r4 but countlees times the peace of mind

 

[Grim-Reaper]

Re: I babied my new 700-r4 for two years...and now I\'m walking!

Thanks for the Props guy! Really needs to got the Steve though...this is his baby.
Number one killer of trannies is HEAT. A BIG cooler is a must on a 700 that's fighting over sized tires. The right Gear ratio in the axles it the other.
If your running 35's and 3.08's or 3.42 you over stressed the tranny and its been over heating. It happens all the time. People get in a rush to get the truck big but make it big before they have solved some other issues. The order that you shoud take when building a truck is always Gears before meats. I'm willing to bet you have the wrong gears for the tires size.
You should be running 4.56 in the axle to take the strain off the tranny. With 4.56's in over drive you would be turning about 2k at 65mph or about 2350 at 75. EXACTLY where you want to be. It will keep the tranny from hunting in and out of OD. The reduced strain recuses the heat the tranny is making.
Under 200degF is where a tranny should run. You start getting over 200 the rubber seals are getting baked. You hit 300degF it's done, the seals will start melting. I read somewhere (I think it came from some Hayden literature that came with my cooler) that a tranny that maintains about 150-160 should go about 200k with normal driving and normal vehicle. If you hit 300 degrees it rated in hours.
Here is a thing I found from Hayden. THis is part of what I was quoting you.
</font><blockquote><font class="small">In reply to:</font><hr />
Transmission coolers help extend the life of your transmission fluid and can prevent transmission failure from overheating.

When your transmission fluid reaches 200 ° it starts breaking down.

At 240 ° varnishes form and transmission life expectancy is cut in half.

At 260 ° the transmissions internal seals and rubber parts harden and major damage starts.

Above 295 ° you transmission start slipping, clutches burn out and carbon forms. With each 20 ° drop in operating temperature, your fluid and equipment life doubles.

Installing a cooler before damage starts and by reducing the transmission fluid temperature by as much as 60 ° can greatly extend the life of your transmission. Installing a transmission cooler can prevent transmission burnout.

[/ QUOTE ]
I run a Hayden Stack plate cooler. Rated for 24,000 GVR. I also have a Hayden Tranny gage. I have only once seen the tranny exceed 200. I was towing a car up a LONG steep grade out of Knoxville area. Semi's were down to 45mph. I hit 220 for about a mile. Once I crested the hill I was back down to 180 withing a mile and back down to 160 within 2 miles.
Here is a picture of the cooler I run.

http://www.haydenauto.com/ I don't think you can buy off that site but Pep Boys carries Hayden.

 

[Emmettology 101]

Re: I babied my new 700-r4 for two years...and now I\'m walking!

Is your filter clogged? Did you ever change it? Also, is there enough fluid in the tranny?

If the fluid is low it wont go without giving it alot of gas and also if the filter is clogged the fluid wont go trhough the tranny and cause similar things.

 

[84_Chevy_K10]

Re: I babied my new 700-r4 for two years...and now I\'m walking!

Every 20,000 isn't enough, but I don't think that was your problem.

Gear ratio probably was. You probably have 3.08s.