700R Transmission

I just bought a 86 XJ6 with the GM 350 and 700R transmission. I am more familiar with the GM 400. In all the gears, it has a rather soft shift. The 2nd gear will flare if I press the throttle hard or give it a lot of gas. My mechanic says there is no adjustment on the 700. Any help or suggestions appreciated! The fluid level is correct and is a bright red.

Richard

Whose kit is on the 700R to install, I wasn’t aware of Jaguar using them?

Change mechanics, then Google GM700R4. I like BowTie Overdrives

Great transmission, but it needs to be adjusted to run with the rear end. The reason I ask is that John’s Kit is pretty specific about setup.

If someone just transplanted one without doing a proper setup you may experience some expensive problems.

These transmissions are favorites of hotrodders, as they will take a lot of horsepower. They wotk nice in Jags too.

if it IS a 700R4 then it should have a TV cable(throttle valve), it should be agjustable , tighten cable increases shift pressure and raises shift point MPH!
i have one and it us great been 25yrs still runnin fine! overdrive makes hi way cruisin fast and quiet!
ron

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“adjusted to run with the rear end” ? Why would the trans care as to the rear end?

Aye, I recall that John has opined that the 700 r has OD and if the car has a 2.88 ratio, it might be a too high final ratio for the torque of the IL 6.

But, others have done it and are pleased, even if .70 x 2.88 !!

The SBC’s can handle the .70 OD x 2.88 just fine.

My LT1 does with the 4L60E. A close relative to the 700r.

Carl

Greetings All,

“Adjusted to run with the rear end” should read, adjusted to the rear end ratio.

Go to BowTie Overdrives and read their article.

Read, re-read, then read again all the tech on Bow-Tie Overdrives. My 700R4 is paired to a 3:54 Power-Lok. Could have went with the 3:90. :crazy_face:

The Bow tie site sends me elsewhere. subscription needed, I chose not!!

So, if you think the Rear cares?/ so be it !

Carl

https://www.bowtieoverdrives.com/

because the load (torque) determines when it shifts. a higher torque engine would cause it to shift early while a weaker one would shift late. lower gears (higher number) will also cause early shifts while highway gears would hold the gear longer. the governor determines when this happens. readily available for cheap or grind off some weight until it is right. a shift kit and different stall converter also effect shift points but I would start with the governor.

Thanks. All quite correct. However, this is in the transmission it self.

But, I see the point, at last!!!

Lower gear ratio in the rear differential effects engine rpm at any given MPH. That effects the transmission shift point. Early shift! 3.31 to 1 as an example

And, a high ratio causes a later shift as to MPH. 2.88’s as in many XJ’s. Mine included.

I did not mess with the 4l60E, a close cousin to the 700r. The LT1 torque pulls those tall gears, event with the .70 OD with alacrity.

Now, some say the 4.2 and 2.88 can’t pull a 700 because of the high OD. others say, no, it does well.

OTH, the torquey 4.2 in my 94 Jeep pulls OD well. No where near as spy as the LT1, but quite decent…

  • of course, at speed, it’s body is a “brick” compared to the SIII.

Different cars are driven differently…

No snow around here, but the Jeep in 4WD and on true M&S tires could go where the Jag dared not…

Carl

given two identical vehicles with the only difference being the governor, they will both accelerate from a dead stop the same and turn the same rpm in forth at high speed. the difference is the heavier governor will force an early shift. it would be in forth at 50 mph lugging the engine at 1600 rpm while the lighter would still be in third turning 2100. while keeping rpm’s down usually improves mileage, going too far lugs the engine and uses more fuel than an engine effortlessly moving the vehicle at an rpm in its ‘power band’. there is no one size fits all but raising or lowering shift points can make an underpowered car more lively or tame a high revving gas guzzler.

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Sounds like a stock 700r4 with a stock torque converter. A shift kit and higher stall torque converter will make a big difference, but wouldn’t be quite natural for an xj6. Adjusting the tv cable as mentioned is crucial for proper shifts. Also, make sure you have the lock-up kit installed properly. A competent trans shop should be able to adjust and confirmed all that

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