RE4R03A Transmission

[TgduMg]

Very good read on the Precision Industries website. Check out the links "The Truth About" and the "FAQs".

[AGM]

Thanks to all for the replies, it is all useful information.

I have been in contact with Level 10 again last night and they have said that they will come back to me with a solution in the next couple of days.

I assume that they resell the Precision industries one and just paint it yellow.

I will keep everyone posted!

Sijoko, No identifiable part numbers on the Torque Converter.

Chally, what is a mines computer and what variables can it control

Regards

AGM

[Chally]

From what I can gather, it looks like a Nissan remanufactured unit with another board inside it.I'll try & find more info on it, somehow.There are no adjustments available, unfortunately...

Chally

[AGM]

I need to establish with 100% certainty that a 1994 Q45 Torque Converter is the same size/dimensions ect as a 1990 Torque Converter.

I assume that if they have the same part number, this would be a safe bet. Could a NICO member please investigate for me if the part number for a 1994 Torque Converter is the same as a 1990 one as 1994-1996 are the only years ever sold here in Australia, so I can't check the 1990 parts listing here.

Regards

AGM

[Chally]

AGM, Sijoko in his post says they have one for the 90-96 models. I would be very suprised if they were different.Does you Nissan dealer deal with Imports? If so, he should have the part numbers on computer.

I'll ring my guy & see if he can help.

Chally

[AGM]

Which year Q45 has the RE4R03A with the model code number51X09. I have not come across this one before.

Regards

AGM

[Chally]

AGM, there are 2 convertors for the Q's. The first one was for the 89-91 models, but they superceeded to the 91-6/93, so they are both the same convertor.The second one is for 7/93 on, for the G50 model.

We can't tell if there is any external differences or even if they will interchange, as the Nissan computer doesn't give sizes.

We suspect that there may be different Stall speeds or maybe modified lockup clutch etc, but this is only speculation.

The 2 part Numbers are as follows:89-6/93 31100-51X127/93 on 31100-51X24

Hope this is a help somehow.

[Chally]

The Model with the code of 51X79 is for the 94 models.

If anyone has an 89-93 service book, you will be able to help AGM by looking at General Specifications at the end of the Auto Tran section.

[90Q45blue]

AGM,

The 51X09 transmission was used for the 1990 model. I hope this helps. Also, here's some information on the transmission if you need it:

Stall torque ratio: 2.0 : 1

Transmission Gear Ratio

1st 2.7842nd 1.5443rd 1.000OD 0.694R 2.275

Nick

[Chally]

Good on ya Nick,

Here's the info for the 7/93 on compared to Nicks.

Stall Torque Ratio 2.0 : 1Stall Revs 2,100 -2,300

transmission Gear Ratio

1st 2.5692nd 1.4793rd 1.0004th 0.694R 2.275

[AGM]

Thanks to all,

I sent Level 10 a 51X65 Transmission, complete with the Torque Converter. I went for this one because of the lower first and second gear. Unfortunatley, I did not get level 10 to ship the 51X65 OEM Torque Converter back to me with the 51X65 Transmission, because I assumed the Billet one would fit. In hindsight I should of got them to send me back the 51X65 Transmision Torque Converter even if it added to my spare parts collection. I am really kicking myself at throwing out this Torque Converter.

What I am left with is a 51X65 level Ten Transmission, an OEM 51X75 Torque Converter and a billet level 10 Torque Converter.

I am in the process of measuring up exactly the 51X65 and 51X75 Transmission cases to ensure that they have the same size case, so my OEM Torque converter will fit with the level 10 Transmission.

My guess is that the Torque Converter case dimensions will be the same, but the Torque Converter internal design matches the gearing of the first generation and second generation gear ratios.

Just to confuse the situation, I have a 1994 Workshop manual to match my 1994 car and I bought a workshop manual which I thought would match my 51X65 Transmission, only to find that the Transmission in this worshop manual is a 51X09. I am really not having much luck with this Transmision modification.

So that my 89 -91 Worshop manual is not totally useless, does anyone know the differences between a 51X65 and a 51X09.Specifically, does my 51X65 have the same gearing as a 51X09.

The whole reason I purchased the 51X65 is for the lower first and second gears.

I hope I have not made yet another mistake.

Regards

AGM

[90Q45blue]

The 51X65 was the transmission used for the 1991-1992 models, with build dates of 6/90-2/92.

I'll see if I can find the specs on that transmission.

Nick

[AGM]

I am sending back the billett Torque converter and getting a custom made Torque Converter made up by Level 10. I will be providing them with all the relevant specs on the car as per the standard form and seek advice on the following areas

'Cam RPM Range' (to be honest I don't know what they mean by this)

'Weight of Vehicle'. I can guess, but does anyone know the actual weight of a 1994 Q45.

'Shift RPM's' of a JWT Timode TCU in sports mode. I know it is a little higher than standard, but need to know the exact shift RPM.

Many thanks to all for the help. I look forward to getting this all sorted out.

Regards

AGM

[Chally]

Vehicle weight WAS 1850Kg without any extras

The Cam RPM Range I'd be asking for clarification, but I expect it to be the RPM where you want the convertor to be working best to suit the engines power dynamics.

[Rex]

...My ECU is the wrong one it truns out and I still shift at 6500 when I should shift at 7300...

Hope that's not out of context.

[maxnix]

I am sending back the billett Torque converter and getting a custom made Torque Converter made up by Level 10. I will be providing them with all the relevant specs on the car as per the standard form and seek advice on the following areas

'Cam RPM Range' (to be honest I don't know what they mean by this)

'Weight of Vehicle'. I can guess, but does anyone know the actual weight of a 1994 Q45.

'Shift RPM's' of a JWT Timode TCU in sports mode. I know it is a little higher than standard, but need to know the exact shift RPM.

Many thanks to all for the help. I look forward to getting this all sorted out.

Regards

AGM

Check me, but

Cam(shaft) RPM Range is it not half of the crank RPM?

Weight of vehicle (dry?) is 4038 lbs.

Shift RPM of JWT is 7300, I believe, but that might be redline. Seems my stock 1995 goes to redline when it shifts. I'll have to watch closely if I can find the opportunity tomorrow.

[Chally]

The cam does turn 1/2 the crank speed, but when talking figures etc, it is always the engine RPM that is referred to.

[1qckser]

'Cam RPM Range' (to be honest I don't know what they mean by this)

I think he means where does the cams/ motor start to make usable good power, I do believe Dennis stated that nothing really happens to atleast 2500 RPMs in the Q motor, so if you look at aftermarket cam ratings they will tell you that depending on lift and duration that the cams usable rpm range will be either street, street/strip, or race, the reason I think he wants to know the cams/ motors power range is to get you the correct stall speed, with your car being boosted the power band has changed as to where you are now making excellent tourque down low so your stall speed probably will not be too big, my 71 Chevelle had a 2800 rpm stall and what a pain in the a#$ that was for everyday driving, with the weight of the Q and the HP and TQ you are making maybe a stall of say 1800 and a flash of 2000 rpms would be a nice daily driven setup, not too much but just enough to get he job done. This guy explains it better than me.

Selecting The Right Torque ConverterBy Phil Parsons

The torque converter (TC) is probably one the most misunderstood pieces of equipment in all of automotive. Hot rodders (even experienced ones) often brag about having a "3500 stall speed converter", without even knowing what that implies (as you will find out soon, a 3500 stall speed converter would generally be useless on any street car short of the most radical of Pro Streeters). Some even boast of having just a "stall speed converter", which displays a stunning ignorance, because ALL automatic transmission equipped vehicles have a "stall speed converter" - it's the number that makes the difference. The whole idea behind different stall speeds is to allow the car to launch at or just below the point where the engine makes the most torque. That way, the engine doesn't have to build up to the peak RPM point - all of the power is right there, on tap. If you've ever been to the drag strip, you have probably noticed that the cars rev way up before the light turns green - this is because most racing engines don't make substantial power until they are spinning over 3000 RPM. If these cars were using the stock stall speed, the tires would break loose long before the engine reached it's optimum RPM. A higher stall speed converter allows the engine to rev up to this optimum point without breaking the tires loose.

So what is stall speed? This is another widely misunderstood term. In the simplest of definitions, stall speed is the engine RPM level at which the torque converter "locks" and overcomes whatever resistance is present to turn the wheels. This resistance is the weight of the vehicle, combined with any other factors (i.e. if you have the brakes on). The old definition of stall speed used to be the engine RPM at which the brakes can no longer hold the wheels still at full throttle. This is not exactly accurate, due to the variations in brake holding power from vehicle to vehicle. In other words, in two cars that are exactly the same weight, horsepower, etc., the one with weaker brakes will display a lower stall speed, even if it really isn't, because the brakes will lose their grip at a lower RPM. The most accurate method for determining actual stall speed on your vehicle is to launch the vehicle at full throttle, and note the rpm at which the car actually takes off (this generally requires a partner watching the tach). This will be quite low on stock vehicles - around 1500-1800 RPM, slightly higher if the engine has been modified.

The next question probably goes something like, "If I already know the stall speed (i.e. what was printed on the box), why would that number change in my car?" The answer is that even though all converters have a rated stall speed (based on a fixed set of torque and weight figures), there are variables that affect this figure, mainly vehicle weight and engine torque. If you are really sharp, you may have already figured out why these two variables affect the stall speed. Weight affects the stall speed because it changes the amount of resistance that the converter has to overcome. A lighter car produces a lower stall speed because the amount of resistance (weight) has been decreased. By the same token, a more powerful engine also lowers stall speed because in the simplest terms, increasing engine power has essentially the same effect as decreasing vehicle weight.

Obviously it is extremely important to know what your vehicle's weight and peak torque is before ordering a torque converter. One of the worst mistakes in all of hot rodding is to buy a converter with a stall speed that is too high. This usually results in a car that is not only slower than it used to be, but also gets horrendous fuel economy and eats transmissions. This is because the converter is slipping all of the time, absorbing power and passing it along as heat to the rest of the transmission. If Joe X. tells you that his TPI equipped 305 Camaro has a 3500 stall speed converter, and you're reasonably sure that he's telling the truth, challenge him to a race and bet large amounts of money on it. Why? At 3500 RPM, TPI in stock trim is pretty much at the end of it's torque curve, meaning that most of the engine's usable torque is absorbed by the converter and passed along as heat. The same exact car with a stock converter would destroy Joe's car off the line, because the stock converter is designed to take advantage of the TPI's excellent low end torque output by using a stall speed of under 2000 RPM, right under the peak torque.

Probably the most important factor to consider when selecting a torque converter is the camshaft. The connection may not seem obvious, but the fact of the matter is that the camshaft basically dictates the RPM level at which the engine will produce it's peak torque, which will in turn dictate the optimum stall speed. If your camshaft has a duration of 220-230 degrees (@ 0.050" lift) or more, you definitely want to think about a higher stall speed converter, probably about 1000 RPM over stock, because the engine will probably make peak torque at well over 2000 RPM. A general rule of thumb is that most stock small blocks (especially TPI equipped) are designed to make most of their torque at low RPM, while small blocks with high horsepower generally lack low RPM torque. Does this mean that you shouldn't bother with an aftermarket converter if you don't have a radical cam? No. Performance converters are usually designed to accelerate more aggressively than stock, so an aftermarket converter with the same stall speed rating as stock will often be more responsive than the stock unit. You just want to be very careful about the stall speed that you select.

Here are some general guidelines for selecting a converter:

According to B&M, the stall speed should be rated at about 500-750 RPM under your engine's peak torque RPM. If you don't know this figure, be conservative in your estimate. You don't want to end up with a converter that has too high of a stall speed. Don't be too conservative, though - it is possible to get a converter with too low of a stall speed, which will have roughly the same effect as too high of a stall speed.

Know your camshaft specifications. If your cam has less than 220 degrees duration (@ 0.050" lift), which most street machines do, you make most of your torque down low in the RPM range, and you probably won't need more than a 2500 RPM stall speed, if even that much.

Have a good idea of your vehicle's weight. Remember, lighter vehicles will lower the rated stall speed; heavier vehicles will have the opposite effect.

High stall converters generate a lot of extra heat. The installation of an external transmission cooler is mandatory with a higher than stock stall speed converter. Actually, you should have one in there anyway. Heat is the number one killer of transmissions - 85% of all trannies die because of inadequate cooling.

The best advice I can give anyone buying a converter is to talk to the manufacturer. They know torque converters better than anybody, and can help you to select exactly the right converter for your combination. This article was designed to give you some insight into what is needed to determine the right converter, and to make you familiar with the terms and what you need to know to speak intelligently with the experts.

K its all explained here

[AGM]

Thanks for the reply guys, especially 1qckser for the tech file.

For clarrification, when referring to the JWT Trimode, it is the TCU shift point, not the ECU rev limiter.

Anyone had the chance to check the gear ratio on the 51X65?

Regards

AGM

[AGM]

Good news! My billet Torque Converter arrived today.I hope it fits and everything is OK. Will report back.

Regards

AGM

[fxjackso]

Just to add to the mix, if you got a Nissan rebuild, under warranty or not, you may have a different year. My 1990's trans (in the NICO parts for sale) as removed, was from a 91, the 51X-65. It was rebuilt and installed in 1995.

[Mav]

Here is some more transmission info.The RE4R03A also comes in the Nissan Patrol. lots and lots of them in Australia.the GQ or Y60 model from 1988 to 1997 definately has them as the auto option (i have one). Not sure which auto transmission the GU (1998+) model has, but i think some of them have RE4R03A's in them, but not the ones with the newer 4.8 litre engine (went to a 5 speed auto).they have the lower (2.784??) first gear ratio.

check out this link for exchange Heavy duty valve bodys:

http://www.automatictransmissi...=8169

And some other stuff including lower stall torque converters (not what seems to be the go for you guys, but good for 4wds off road)http://www.automatictransmissi...10672

Enjoy

[HeavyDuty]

(Prairie dog stance.....ears perked up)

4.8?.............hmmmmm.

[Mav]

Stop thinking about the 4.8!! it is an inline 6, cast block and a relatively measly 185kw (around 240 hp). And it only came with the 5 speed auto (or manual) behind it.Stick with the Vh45 for sure!the other patrol engines found behind the RE4R03A are a 4.2 (125kw), 4.5 (?) and a 4.2 diesel (pittiful 85kw).VH45 kicks all by a vast margin.

[HeavyDuty]

Stop thinking about the 4.8!! it is an inline 6, cast block and a relatively measly 185kw (around 240 hp). And it only came with the 5 speed auto (or manual) behind it.

4.8 liter inline six? Wow, with a strong cast iron block & proper rotating assembly, a single T100 Thumper, http://www.turboneticsinc.com/thumper.html 1000cc injectors, 4 inch downpipe, somebody stop me.

If I don't sell this RB26 soon, I'm gonna get stupid with my daily driver........

[maxnix]

4.8 liter inline six? Wow, with a strong cast iron block & proper rotating assembly, a single T100 Thumper, http://www.turboneticsinc.com/thumper.html 1000cc injectors, 4 inch downpipe, somebody stop me.

If I don't sell this RB26 soon, I'm gonna get stupid with my daily driver........

Nah, go for the Caterpillar swap. Talk about cast iron!__________________Brian1995 Q45 & Q45t & 2000 Q45

Discover the power of the button!

[Infinitiguy19]

As to JWT trimode you have to understand that the tcu has all these functions built in [jumpers on circuit board] and JWT is just running wires out to a 3 position switch.

Stupid question but does one need a JWT board or can one just make a JWT Transmission Control Unit (TCU) by opening up the stock TCU?

I opened up the stock TCU (1993 Q45 first gear start (Not the rare one)). And I found nothing obvious but I do see many jumpers...

Please move this to the Q45 Section!

[Ace2cool]

Please move this to the Q45 Section!

[OwnerCS]

Did I miss something or did AGM eventually report back with the conclusion to this story?

On the flip side, my 91 seems to like the 94 TCU and NICO ECU combination.

[maxnix]

No, AGM supercharging project never matured that we know. He was in Perth when this was all occurring.

The later TCU allows the revs to go higher before shifting with the shorter 1st and 2nd gears of the early transmission.