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1970-1995 Range Rover Classic
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Discussion Starter #1
I am still trying to track down why my 89 Rover with 4.0 stinks in performance.
I basically have to drive it like a manual.
When using the automatic, It shifts into 2nd really early and I cannot get it up to speed for a very long time.
When I shift it manually, I shift around the 3000 range.
It still starts a little slow, but once it hits 2000 rpms, I can feel a power boost. Almost like it is actually coming alive and power is where it should be. ALMOST

It does jerk into gears just slightly

I still cannot make it up long hills without pulling over to cool down and to let a group of cars go around.

My favor is... Can someone tell me what RPMs yours is shifting at? I think it does shift differently if you floor it through the gears vs just gradually.
I would love it if I could get both readings.
Could my torque converter be shot? trans slipping? Vacuum leak somewhere?

Thanks all
 

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I think what you're experiencing is normal. I've had five or six Classics and they shift the same, quick 1-2 upshift. There's a trans bowden cable attached to the throttle body linkage that helps to determine when the trans should shift up and down as the accelerator pedal is cycled. I found that adjusting the cable out/tighter can influence a later upshift at higher RPMs. You will also notice the trans will downshift sooner when pressing the accelerator. I drove my truck with it this way for a while but ultimately didn't like it. Also I noticed my fuel mileage adversely affected.
 

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1989 Range Rover Classic
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So mine annoys me with this same problem, it shifts way to darn early. When setting off vigorously (not floored, but some healthy right foot), it's already into 2nd by 1800-2000ish, then it will hold second a bit longer before going into 3rd at about 2400, then fourth at around the same. If I want it to spin up to overtake or something, I just drop it down manually. If you floor it it does hold for longer, 3k+, but otherwise it shifts soon.
 

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Light throttle on my 1991 3.9 zf 4 speed, 2nd about 15mph, 3rd about 25mph, 4th about 35mph and locks torque converter at 51mph exactly.

Unsure if you are on 3 or 4 speed?

Wide open throttle, it'll shift right at the red line all gears.

Pulls easily on long uphill if revs are near torque peak of around 2900 rpm.

Fully laden on steep hill fast road it'll take a while in top gear to get it accelerated from 50mph for example, but manually pull it into 3rd will be faster. It has no real problems maintaining road speed although it's certainly not dramatically quick.
 

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Unfortunately I’m not have those problems... when I give it gas it goes and shifts good...
Have you considered your haveing a back pressure problem ...
Just a thought..
but do check the kick down cable
It can cause a problem if it is broken or
The cable is rusted and locked up...
It is a valve...
It is a pain to replace ... but not hard...
Again... just a thought
 

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1970-1995 Range Rover Classic
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108 Posts
Discussion Starter #6
Thank you guys for the replies.
I must have another problem then.
Gear 1 shifts to 2 around 1800-2000 and about 10 mph then it takes forever to get up to speed.
Every other gear shifts at approx 3000.
I typically have to floor it at all times until I get up to speed. Usually takes about 30-40 seconds to get up to 50-60
Getting on freeway can sometimes be very scary

I have messed with the cable. I adjusted it to shift later, but I didn't like it. It took too long in my opinion to shift in every other gear except from 1 to 2
 

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1970-1995 Range Rover Classic
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247 Posts
Change the fluid and filter - opinions vary on this. I would continue to adjust the cable - I have found a turn or two makes a considerable change.
 

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1970-1995 Range Rover Classic
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108 Posts
Discussion Starter #8
The fluid looks really clean although when I do get home from a drive, I do kinda smell a burning odor.
About a year ago, I did pull the drain plug and let it drain and added back the correct amount. However, I think that does not really get it all. Am I wrong?

What is the best fluid to put in? (I dont want to get into a brand and whos fluid is best debate.) Is there one that is just known to be good for these transmissions?
 

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1970-1995 Range Rover Classic
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Being new to Classics I was a little concerned with the same thing. Then after reading the manual (mine is the three speed in the 1985) it appears that's it's normal. You just needed to give it more gas to force the kick down panel to kick down. Here's a clip from my manual, perhaps the Rave Manual has the updated data in the Transmission PDF.

286334
 

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1970-1995 Range Rover Classic
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108 Posts
Discussion Starter #10
I have the 4 speed. I think its a bit different. I could be wrong.

Something that just came to mind. When I took it into the Rover shop about a year and a half ago, my trans cooling hose was leaking. The mechanic tossed my hose into the trash and bypassed it so it is not going into the radiator. He said it was temporary while he did other tests. When he had it for 3 months and nothing was done, I just had to go pick it up. The trans cooling is still bypassed.
Is this bad?
 

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Discussion Starter #11
No no no,please forgive me. I am wrong. It is the engine oil cooler. The hose from the oil pump to the radiator and the hose back to the pump is bypassed.

Very sorry.
 

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Longer term it would be wise to reinstate the engine oil cooler circuit, short term you could reduce oil change intervals to make sure you don't compromise oil condition. It certainly wouldn't give you the condition you currently have regarding power.

It just looks like your engine is not producing anything like enough torque, even to get close to standard power levels.

Very quick and basic test. Start from cold, run 15 seconds and switch off. Then touch each exhaust outlet on the exhaust manifold right by the cylinder heads, you need to see if all of them are warm ( no cold cylinders) then post what you have.

Also to check, with engine not running. Get someone to hold the throttle pedal flat to the floor, then see if the arm on throttle body (the engine end of cable) is fully opening. This to see if you can command full power.
 

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If you have the 3 speed Chrysler torqueflight 727 I would say your shifting pattern is normal. The 4 speed ZF is a superior automatic. I had the 3 speed in my 1983. It was mechanically perfect with 35kmiles but was leaking through the various seals. I recently replaced it with a 5 speed LT77 as I prefer a manual gearbox. I have the 3-speed in the garage if anybody wants it (hint).

I had the 3 speed for about 2 years. It is a very strong gearbox that is very common in the USA and popular with hot rodders for taking a lot of power. It is a smooth shifter build for comfort and you need a big engine. Parts are very common and you can buy kits that change the shift pressures to get higher shift points. Tons of instructions online. Tightening the throttle linkage does make things a bit more lively but only goes so far as the shifting gets jerky or it fails to shift up altogether.
 

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1970-1995 Range Rover Classic
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Discussion Starter #14
Ok all.
I made a big leap in progress.
I had my girlfriend get in and throttle it.
I noticed that it may have just slightly more room to go.
So there were a few issues.
I turned the idle screw up a little and that gave it more room although did not change the idle speed (that I could tell.)
I then checked the carpet and, while it looked stock and neat and clean, there was the driver carpet, the center hump carpet, and the rubber undermat all meeting at the same spot which left a hump and the pedal to not go to the ground.
What I removed and what I did at the throttle cable seemed so minute, that I am super surprised that it drives so much better.
Next I need to go hill driving, because then I will know for sure.
My test drive around the block was night and day difference tho. It kicks down automatically and when it should.
 

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Sounds like significant progress. Will wait to see your "gradient" running report.

Some detail, your idle screw, by that do you mean the collar that is on the throttle cable that controls the slack in the cable at rest?
If so, I set that by turning it until the slack on the visible part of the cable is almost taught, then back it out again just a little so that it will always have just a small amount of working slack. That way the throttle cable can never hold the idle speed in elevation. Idle on these is only controlled by the ecu if mechanical setup is correct.

Be interesting to hear how your more extensive run out goes. It should be capable of running right up to red line before changing there if wide open throttle is competent. If when warmed up you let it change up to second gear and then floor the throttle completely it should go right through rev range.
 

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More thinking out loud, but helps to understand.

The engine end of the throttle linkage has a non linear arc for the cable to turn the throttle plate. Early in the pedal travel gives slow/soft response to allow a finessed modulation of engine power at low speeds which keeps response smooth in normal operation. The last 3rd or less of pedal movement probably accounts for more like half the upper end of engine response. In other words it gears up in that sector with any consequent losses apparently much more in the furthest reaches of foot pedal travel.

In all probability, you appear to have been operating it at something like 50 to 70% demand unintentionally. Hence the play out on gradients in particular.

Could probably call that the "economy mode" sir ;)
 

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1970-1995 Range Rover Classic
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Discussion Starter #17
RRLondon. I can't thank you enough for your help. It has been huge.
Raining/snowing here, so I can't get a great idea out there, but I went and drove a hill that I typically have trouble with and it was great. Much easier.
Thats a help knowing where you set your "idle screw" or whatever its called. I am going to set mine in same exact spot and then play from there where the car runs the best.
One thing also. 1 of my springs is broken on the plenum for the throttle. The throttle springs back just fine with the other 2 springs, but I am curious how needed the 3rd one was
 

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How are you getting on with it Gerk?

Had a chance to look at my throttle linkage today regarding your spring question. Which one is broken as two are return springs at either side, with the centre one being for holding tension in the gearbox kickdown cable.
 

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1970-1995 Range Rover Classic
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Discussion Starter #19
Hey London,
I am officially enjoying my Rover. Only took a couple years and three engines to figure it out.
I still feel like I am missing some juice, but I am not going to fret it. I towed a snowmobile up a very long hill yesterday and spent most of my time between 1st and 2nd. It did not like me very much after.
Thank you for asking
The spring is the one furthest to the left (left hand drive)
 
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