700r4 swap questions

[NEWFISHER]

I'm getting ready to swap the motor/trans and rear axle assembly out from under my 1950 Suburban. Removing a later model 250 hei, single carb, stock manifolds set up, a sm465 granny low 4speed and the ( apparently rare dana) rear axle assembly with 3:08's . I'm installing another fully built ( bored, milled, cammed, 6=8 with a Holley) 250, an MD8 cased 700r4 and a 10 bolt rear axle from a 68' 2x with 3:73's and posi.

My question(s) to those who have done the 700r4 swap:

*Speedo cable from the 1950, will it screw into the 700r4? If not waht cable/adapter have you used?

*What are you guys doing for lock up? This is what I was thinking: http://www.jalopyjournal.com/forum/s...ighlight=700r4

*Are the inline dual pass oil coolers worth using? Thoughts are to mount it on the frame rail near the trans

Thanks guys and gals

[solidaxel]

I woud say yes I have found all the chevys to be the same in the modern vintage, 55 and up. You will need to change the driven gear on the side of the transmision to conform with the 3:73

[**grumpy**]

Great info.
700s are great if set up right.
I just bought a supposedly late 80s 700 from a 40k mile wrecked camaro.
hoping to make it work in my 55 1st

[parkwood]

This what i used on the suburban with a 700r4 and have had no problem.

[NEWFISHER]

Paarkwood; I just read through your build threads and saw the cooler, I ordered the 18 inch one earlier today and thought about mounting it in the same spot. That Burb is a work of rolling art! I love the faux wood idea you used.

I ran the vin from the 700r4 donor and the rear ratio is 3:73, same as what I will be using. Thanks for the heads up on the cable. Just need to do the lock up mod and I will be set. Trying to get everything lined up to do each section in a weekend each. First the rear axle and sids front axle swap , drive it a week and then the engine/trans swap. I have a lift and a shop to use but have to be in after 6 on Friday and out before 7am Monday each weekend.
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[bk2life]

[QUOTE=**grumpy**;5719589]I just bought a supposedly late 80s 700 from a 40k mile wrecked camaro./QUOTE]

double check the info on the board/google searches, but if im thinkin right the early 700r4s arent as good as the later 90s 700's.

i remember my brother had a mid 80s irok and it ate convertors.

some reasearch will give you the goods and bads..

[Oklahoma_k5]

On my 87 TBI the computer does a crappy job of controlling the tc now with all the driveline changes. 203-205 doubler and 4.10 gears in a 14 bolt.

So I left the switch on the brake pedal to control the ground. And a switch to control the power. On the highway I lock it up. In town I leave it off. If the trans is in 2nd, 3rd, or 4th and the switch is on the trans is locked up until the brake pedal is pushed.

It is a little hassle to flip the switch but not as big of a problem as always listening to the motor rpm to hear if the computer has the tc locked or unlocked building heat trying to cook itself.
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[Oklahoma_k5]

Personally I don't like the idea of the tc only locking in 4th. My 99 dodge 1500 unlocks the tc and down shifts on a hill. Jumps the rpms too much. To me it's annoying. Have to down shift the trans manually to get the tc to lock back up.
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[1project2many]

Without making this a huge deal...

1) The 700R4 (also known as 4L60) has gone through many, many, many changes over the years. When searching for one try to find the latest version possible (last year = 1992), or one that was rebuilt by a shop that installs as many upgrades as possible. The list of factory upgrades and updates is almost three pages long and the aftermarket has come up with a few more on their own.

2) Many, many 700R4 / 4L60E failures are due to heat. Multiple factors contribute to how much heat is generated in a transmission including vehicle frontal area, GVW (including any trailers), engine power produced, vehicle speed, transmission gear ratio, final drive ratio, and amount of torque converter slippage. The most conservative treatment of this transmission will always install the largest cooler possible in a place where there's plenty of airflow and will use lockup whenever possible (in reference to the thread previously linked).

There are several methods to lock the converter which vary in complexity and ultimately, in how the vehicle feels when driving. The 4th gear switch in the previously referenced thread is ok but that makes the shift feel clunky or clumsy to me. A vacuum switch which closes at about 11-12" vacuum can be added to that circuit so the TCC will unlock under load in 4th. Unlocking the TCC assists acceleration. Additionally, wiring in a light that illuminates when the TCC is unlocked is a good safety device. If you find yourself on a long trip and the light is illuminated more than it's off, time to shift down to drive.

With a computerized engine it's a very simple job for someone who edits chips to adjust TCC settings. There is no need to install any external circuitry.

Yes, the speedo cable should fit without problems.

[ozzie50]

I am at the same spot with the same questions. I have done a lot of shopping around for a kit and these guys are probably who I am going to go with for everything. http://www.bowtieoverdrives.com/index.shtml I have called them a lot at always get to a tech guy very quickly.

[sickred72]

PM me and i will get you guys the nw hook up on the tranny and converter, you can still have 4th gear lockup with the painless kit or you can do what we call a dummy lockup, so its like a th350 or th400 with an extra gear. for you guys that are looking for a tranny to swap out get a 1991 up 700r4, they come factory updated with aux. valve body. for you guys that need a little more stall use a 4.3 liter converter which has a factory stall of 1999 stall ( 2000 stall ) opposed to the 1400-1600 that come in the 5.7. I've been in the converter manufacturing business for 23 years.

[1project2many]

for you guys that need a little more stall use a 4.3 liter converter which has a factory stall of 1999 stall ( 2000 stall ) opposed to the 1400-1600 that come in the 5.7.

If going this route and looking for used parts be sure the converter clutch type matches the clutch control system. Easiest way is to get converter for year of trans. Also good is to get 4 letter code off OE converter if possible and use online resource to decode TCC type.

[NEWFISHER]

In my first post I linked an easy wire seat up that sounded pretty good. I have been to a couple trans shops and showed them the procedure to get their thoughts. Both said it would work, but would give a very harsh bump or feel when downshifting out of 4th and unlocking at the same time. Both shops recommended using a brake pedal sensor style or fabbing up a vacuumm style from a mid 80's fuel saver Gvan Th350 into the solonoid for the 700r4. Niether one offered "their kit or fabbed system" which made me feel like they thought I was a DIY guy and was genuinely helping answer some questions. I will probobly have one of them install which ever system I end with and have them adjust/set TV cable and watch line pressures etc.

I looked a little further and found a couple different kits. I DO NOT want a switch on the dash to have to manually lock TCC unless its for a tow-haul feature in 3rd. I want it to be as seamless and factory feeling as possible on both up/down shift and lock up without having to step on the brake, flip a switch or rub my stomach and pat my head while driving. Bumping it to the top to see what " systems" you have run and what you think would work best for a daily driver.

Here are a couple:
http://www.summitracing.com/search/p...r-lock-up-kits
.
http://www.tciauto.com/tc/200-4r-700...iring-kit.html
.
http://www.73-87.com/7387garage/drivetrain/lockup.htm
.
http://www.bowtieoverdrives.com/cata...php?ITEMID=332

[1project2many]

What I described is what the trans shops are recommending. As a tech and "hot rod guy" I've worked on and adjusted plenty of other people's setups. I haven't done a non-computer controlled TCC in years but when I did I'd install a vacuum switch, 4th gear switch, and brake switch in series. The extra light is to indicate a condition which may overheat the torque converter and it is optional. Factory lockup in the early cars with TCC sucked. It bumped, it locked at the wrong times, it was too busy. It was far from seamless. But it was automatic. Chances are that no kit will give you the drop in performance you want but most should give acceptable results. The kits in your searches seem overpriced for what's included. Some of them do not include the vacuum switch which I'd avoid. The 73-87.com parts list and instructions are more my style.

HTH

[NEWFISHER]

1project2many
Thanks for the input. Ive been searching for 3 days and reading as much as I can and agree that none will be like factory without all of the electronics, but close and the 73-87 system with vacuum switch seems like the best option. I ran all of the GM part numbers and most are disconntinued. i will try to cross reference them with one of the trans shops aftermarket parts lists and add them here.

[NEWFISHER]

Found this diagram including the vacuum switch and also ads a light to idicate lock up in 4th

[1project2many]

Sorry. I guess that I forget this is still new territory for many people. Designing and wiring a simple control circuit for TCC can be a simple process. Having a trans shop do it may help but there have been soooo many changes and upgrades to that trans that you may leave the shop with your head spinning and your wallet substantially lighter. Nothing wrong with using the shop but it's a good idea to remain focused if things start to get out of hand.

There are many different combinations that can be used to achieve converter lockup. One way to approach it is to list some of the requirements or conditions.

For example: GM used a dual brake switch or a separate brake switch that was normally closed but would interrupt power to the TCC when the brakes were applied. If you do not have a provision to use the OE style brake switch and cannot add a separate switch then the relay in the posted circuit will do the same job.

The 4th gear pressure switch should be a fairly easy item to find. One source for transmission parts is TranStar. They are a fairly large supplier of trans kits and parts Transtar GM catalog. I have purchased directly from them before but they may frown on it for small purchases. However, a local trans shop could get what you need through them. The normally open / pressure closed switch part no. 8627332 was originally used for "Transmission Controlled Spark" on turbo 400's and is available through Transtar as part no 34414. The THM400 connector part no 24205373 is Transtar part no 34444A.

Vacuum switches are often easier to source through aftermarket sources. From the kits previously linked, the "fully adjustable vacuum switch" is a desirable item. I believe that was from TCI. A less expensive but similar part made by Superior co is available through Transtar as part no 74439A. Here's an Ebay link to one of those switches. 14014519 is available through the aftermarket as Standard Products VX2. The pigtail is somewhat unique and is probably better than the slim spade connectors. The price of the Standard part is near the price for the adjustable switch so I'd probably opt for adjustable.

The light in the posted circuit is on whenever the TCC is locked. To me, I don't need a light to tell me "All systems are functioning OK" but one which indicates "potential problem here" is better. Also, on long trips or at night I might find the light that is on more than off to be annoying. A simple change, wiring the light in parallel to the vacuum switch, would cause the light to illuminate only when the trans is in 4th gear, the engine is under enough load so the vacuum switch is open, and the brakes are not applied. I can draw a circuit for you when you decide which components you will use.

[NEWFISHER]

Thank you, that is all great info. The part numbers really help! I am leaning towards the above diagram, but using the LED along with a toggle to lock up in 3rd when towing. The vacuumm / brake switch through relay system seems to be the softest in/out system. I appriciate the help as it's my first rodeo on a 700r4 set up. I have searched and my head spins with all of the " you just need to do this" but most fall short on help. Your diagram along with the transstarr part numbers would be a great help
Thanks

[1project2many]

Posting this here to complete the thread. This diagram uses pressure switches for 3rd and 4th gear as well as a manual toggle switch to enable lockup. The vacuum switch included prevents lockup unless vacuum is high and engine load is low. The relay opens and disables TCC when the brake pedal is pressed allowing this circuit to be used with the existing brake switch rather than finding and installing a TCC specific switch. The diagram is here in both .jpg and .pdf format. If my messy writing is unreadable or if there are any questions, don't hesitate to ask.

[NEWFISHER]

Thank you! After all of my research , that sums up everyones opinions and real-world driving. The vacuum switch seems to be a key component and running a relay on the brake circuit is a better design ( especially on these older floor pedal brakes) and when used together work well. Those with the simple system use thiers , but those who have set up to this or similar systems agree that it works smoother. I will be installing a switch and an led light to lock up in 3rd when towing.

[1project2many]

No problem.

The 4th gear pressure switch should be considered a primary switch while the third gear pressure switch and toggle switch are optional. If the toggle switch is "on" the trans will try and lock TCC whenever vacuum allows. This could make for interesting in town performance so be sure and turn switch "off" when you're doing frequent stop and go driving. Most vintage trucks don't have a hazard/warning light system installed but an aftermarket system which applies power to the brake light circuit would cause the TCC relay to cycle on and off when the lights flash. A truck equipped this way should have a diode installed to prevent power from the flasher from reaching the relay.

[NEWFISHER]

Update: roughly 26,000 miles since last December and the 700r4 is a rock star. Since then I have acquired a 65 C10 350/700r4 and using the TCI kit has been a flawless , user friendly trans.

[NEWFISHER]

To answer the first questions:

Yes, the factory cable works great

I have since used the TCI vacuum switch set up and also wired a friends using the supplied diagram in this thread.

Yes, the inline dual pass coolers work well frame mounted, even towing a 20' travel trailer all summer in the mountains here in the NW. The only draw back is the thermal sensor in the 700r4 that will not allow 4th gear shift to happen until trans reaches operating temperature, no biggie just don't drive over 55 for the first 10 miles or run a radiator internal cooler in conjunction with the frame mounted external one.