Let me make it clear about The Great Overdrive Debate: Should a 700R4 is used by you Or 4L60E?home select
There comes time whenever spinning that small-block to 3,500 rpm so that they can avoid being go beyond regarding the freeway becomes tiresome. This quickly contributes to considering an update to an overdrive automatic. There are many good reasons why you should select either the 700R4 or the 4L60E. Both provide the advantages of an overdrive, and determining involving the two, the selection boils down electronics or no electronic devices. We won’t make excuses, convenience comes at a high price. As Mark Twain when penned вЂњYou will pay your cash, and you also takes your option.вЂќ
The difference can’t be told by you from a 700R4 and a 4L60E by the oil pan because they are almost exactly the same. In the event that transmission has a sizable 18-pin electronic connector above the passenger side pan train, it is a 4L60E, as seen right here. If this has a cable connection nearby the cooler lines on the passenger’s side, that is a 700R4.
The very good news is the fact that in any event, you winnings. Somewhere else in this whole tale we’ve detailed the ratios of both the TH350 and also the 700R4/4L60E. Whilst the 3.06:1 First-gear ratio would seem become an edge on the TH350’s 2.52:1, the drawback with all the much deeper very very First may be the major rpm fall when you look at the 1-2 and 2-3 gear modifications that the 700R4/4L60 force upon you. At component throttle, it is only a minor problem since converter slippage absorbs all the distinction.
The advantage that is obvious the overdrive could be the 30-percent decrease in cruise RPM. None with this is breaking news, and both transmissions provide exact same benefits. Now let us enter into the thing that makes them various by first investigating the 700R4. Advantages begin with something which’s essential to everyone вЂ“ cost. If you are re looking for the utilized transmission to rebuild, only the versions that are non-overdrive less costly. The advantage that is big вЂњanalogвЂќ overdrive offers over its electronic compatriot is you do not require a stand-alone controller to use it. Straight away that puts the 700R4 ahead when you look at the cost war by $600 to $1,200.
The Achilles heel for the 700R4 could be the television cable adjustment. Tens of thousands of 700s have actually died as this adjustment is wrong. This contributes to low line force that smokes the clutches. Be forewarned, this will happen rapidly.
Then, the 700R4 is a lot easier to put in as it doesn’t require any thing more compared to television cable hookup, shortening the driveshaft, going the crossmember, and including a 12-volt supply to the transmission. You’ve got the luxury of selecting a lockup converter, and you can find kits open to secure the converter once the transmission changes into overdrive. This does, nevertheless, need the usage a brake light switch that is special. They are easy and cheap to wire to the transmission. This switch cuts capacity to the transmission whenever you move from the braking system pedal, which unlocks the converter.
Another advantage that is minor the 700R4 is the fact that it includes an old-school speedometer cable, therefore updating an adult framework is not difficult. The transmission fits into many very early transmission tunnels fairly well, although, there can be some small flooring pan tweaking required.
This takes proper care of the benefits. Now, we are going to go to your disadvantages with this gearbox. The biggest detriment, plus the product that many frequently receives the blame for 700R4’s being disabled in the roadside, could be the dreaded television cable. A cable is used by the 700R4 that links the throttle linkage to your transmission’s throttle valve (TV) into the valvebody.
This is actually the governor that commands WOT up-shift rates. It utilizes loads and springs exactly like a technical advance procedure in a supplier, but employs two sets of loads for low and high rates. The governors in TH350, TH400, and 700R4 transmissions are identical. For the record, this senior sizzle picture is of the governor in a TH350.
The television cable basically replaced the cleaner modulator valve which was the strain sensing device when it comes to transmission. The valve within the valvebody and increases transmission line force because the throttle starts. This might seem to be a easy procedure, sufficient reason for stock elements, it is hardly ever a problem. However with aftermarket carburetors, EFI throttle bodies, and linkage that is various, the chance for errors is rampant.
You can find volumes of product written on establishing up the television cable, and in the event that you have it right, the machine works great. Nevertheless the trouble will come in establishing within the linkage corrections to achieve this task. It’s not simple, as soon as misadjusted also somewhat, the purchase price is generally a wasted group of 3-4 clutches вЂ“ a repair that is expensive. The net is saturated with unfortunate tales of burned off 700R4 transmissions whose fault that is only a poorly modified TV cable.
Setting the WOT up-shift rpm on the 700R4, you’ll need a TCI kit such as this the one that offers stiffer springs to carry the changes in at a later RPM. It is a headache, nonetheless it can be carried out.
If you should be operating a late-model motor like an LS with production EFI, there’s absolutely no factory supply for a television cable because these engines had been loaded with the subsequent electronic 4L60E version transmission. You are able to adjust A television cable to an LS2 as an example, and contains been done effectively. But, it really is still another reasons why the 700R4 is a lot more of a challenge to tune correctly.
Another small annoyance is wide-open-throttle (WOT) up-shift is primarily based on the governor this is certainly driven from the transmission’s output shaft. Most rebuilt 700R4’s uses extremely heavy loads and light springs on the governor that may signal the transmission to up-shift at extremely engine that is low. Needless to say, it is possible to manually move the transmission at any RPM you desire, however, if you need to adjust the WOT that is automatic, this might simply be carried out by changing the governor.