My Experience with 5 speed conversion

[Jerman]

very good consumption....
i think waja pun kalah...

Mana boleh? Waja boleh dapat 10-12km per litre:top:

 

[Vincent Hor]

Update : Did a trip to Penang recently and this is the result.

Distance covered : 965 kms
Petrol consumption : RM262
Petrol Price : RM2.45/litre
Works out to : 27 sen/km or 9.02km/litre or 11.08 litres/100 kms
Average highway speed : 120kmph

 

[BrianJ]

Good stuff Vince,
Im gonna get my Jatco 5 speed conversion done on monday.
Been doing some research on this trans and it seems to have its design roots similar to the bullet-proof American TurboHydramatics.
Great...

 

[Vincent Hor]

Brian, no regrets. This gear box runs smooth and pretty strong. For better acceleration use the rear diff with 4.10 However the 3.91 supplied with the conversion kit is quite well matched by the Japanese giving a good balance for off the line acceleration, cruising speed and reasonable economy.

I would suggest that you use the 3.91 diff in your initial installation. Have a feel of how the car drives with this diff. Later you can plonk in your 3.23 diff by swapping the rear diff output flange to compare the performance. You will probably get even better fuel consumption and the very nice cruising speed of 160 km/h at 3K rpm. Super quiet and just nice for your ususal long distance drive.

I wish I could find a 3.46 or 3.64 diff as I have always enjoyed this gearing ratio when I had my E23 728i and the E28 528i. It would be a good compromise between the 3.91 and 3.23

Good stuff Vince,
Im gonna get my Jatco 5 speed conversion done on monday.
Been doing some research on this trans and it seems to have its design roots similar to the bullet-proof American TurboHydramatics.
Great...

 

[BrianJ]

Thanks Vince for the detailed infor.
I'll let you know how it goes after the conversion.
Happy Cruising

 

[Vincent Hor]

Brian, so how did the conversion go? Can confirm if it was 6 speed or 5 speed? Anyway I did the count too, seems like there were 5 changes.

But the Jatco part no RE5R02A seems to suggest it's a 5 speed. Maybe it's an overdrive gear.
There is also a RE5R01A which is what some of the hulf cuts come with.

 

[ALBundy]

I wish I could find a 3.46 or 3.64 diff as I have always enjoyed this gearing ratio when I had my E23 728i and the E28 528i. It would be a good compromise between the 3.91 and 3.23

Bro, there is plenty of 3.64 around, mainly from the E34 M50B20. My E34 is running on 3.64 as well. Tried 3.46 (this one is a little rare as this ratio is only available with the E34 w/ Manual transmission) but at the end still went back with the 3.64 which I think is the best for the 5 speeder

Cheers

 

[BrianJ]

Ok,...... been doing constant long hauls every 2 days Melaka-KL-Melaka-KL......... over this last week and all seems well with the Jatco 5spd.

Yup i do get 5 up-changes,... does this box have a 'lock-up' once u get cruising?

The 3.91 is a bit too tall for my liking and would prefer to get hold of a 3.64 since i spend most time on the highways.

From my personal experience the ZF 5 speed box is more spirited compared to the Jatco 5 spd , although i guess the Jatco will get the job done and remain more economical in the longer period.

Cheers

 

[JOKER]

Soo bad la....

Just to share my experience on the conversion of the 4 speed GM auto gearbox to a Jatco 5 speed on my E34 M50B25. Reason for the conversion was symptoms of a failing torque converter. Hopefully this will give some confidence to some of you who are thinking along this route.

Thanks to Albundy and Kevster whose positive advise help me in my decision making.

The job was handed to my regular mechanic Albert Fang of WP Auto in Pandan Indah. I must say that he knew exactly what to do and there was absolutely no hitches at all. I also took the opportunity to replace the flywheel oil seal.

It seems like a plug & play job. The following were sourced from a Japanese half cut which has only clocked 87,000 kms

1. Jatco RE5R02A gearbox
2. Longshaft
3. Rear diff 3.91
4. Gear shifter mechanism & sensors
5. Oil cooler & relevant pipings
6. Gear box ECU with complete g/box wiring

Albert just delivered back the car this afternoon. So far I am enjoying this new experience. The gear box seems more responsive through out the gears. It's running at lower RPM's compared to the GM 4 speed. 110 kmh is at about 2.2k RPM. According to Albert who tested the car last night, it was doing like 140 kmh at 3K RPM. Gear shifts also quite smooth. Although not tested yet, I believe outstation drives should yield better fuel consumption.

Total cost RM3,700

soo bad, i just perform topsecret XXXXXX DIY, the gearbox was A4S310R...
after XXXXXX, i drive the car at 80-90km/h with 1500 +/- RPM, E-mode...
the 18 buttons board computer show 5.5L/100km fuel consumption........
the fuel consumption rate will increase if the speed drop or rpm increase...

i drive that slow coz the police was shooting radar/laser gun and try to trap people...

the sound like ferrari modena 360...when hard accelerate...in S-mode..:34:

 

[macgy]

My e34 is showing sign of GB problem, i have read this post with great interest and decided to follow what Vincent has done, thanks Vincent & Albundy for the tips, so i am going to change my GB to 5 speed Jatco GB with a 3.64 differential next week, my mechanic has warn me however that the Jatco GB won't be smooth as the old GM 4 speed GB. Will keep u guys update.

 

[ramsing]

how u know wet feeling? u licked him dry after which issit? BWAAHAHAH.. memang hamsing

nola...same like how u tell me u always play with ur gearstix in your oren until got sunkist fresh juice wahhahaha....how gbox? time for manual laaaaa

 

[macgy]

must have gone kuku :stupid:

 

[macgy]

Got my e34 changed to 5 gear jatco, no obvious jerk from 2nd to 3rd gear as others experienced, gear change is smooth, i will continue to use the 3.91 rear differential for a while before i try the 3.64 but already i am happy with 3.91, not sure whether i should change to 3.64, well will decide later.