Anyone using synthetic transmission fluid?

[Roverfire]

I'm coming up on my 60k service and I'm thinking of having the transmission flushed and filled with synthetic fluid. A local shop will flush, change the filter, and refill with Amsoil fluid for $140.00. It's only $50 more than if they were to refill with reg fluid. I figure synthetic is worth the extra $50 but want to make sure that it is compatiable with the transmission and won't cause any problems.

 

[jsonova99]

This is a good question, I'm curious to here what everybody's thoughts are

 

[David T]

I have been using Castrol synthetic fluid in my transmission for approx. last 2 years . Original problem was transmission over heating when towing a heavy car trailer up some hills and when driving on loose sand beaches.

Since using synthetic I haven't had an overheating light show up for gearbox at all. I like it but some specialists don't advise using it Up to the purchaser I guess

 

[JSQ]

I use Mobil1.

Amsoil is good to.

I'm not that into BG yet. Gotta be convinced first.

 

[alex3324]

A local shop will flush, change the filter, and refill with Amsoil fluid for $140

Hey Roverfire, tell us if you have a DI or a DII. $140 to drain, replace the filter and replace with synthetic is a steal for a D1. It's an OK deal for a DII. On a D1, the exhaust Y-pipe needs to be 'finnessed' if not partially removed from the truck in order to drop the gearbox sump to change the filter. Make sure you get this price in writing before they see under the truck.

 

[Roverfire]

I have a 99' Series II.

 

[parthog]

I use the Mobil 1 in the LR transmission and other cars, Allison Transynd synthetic in the big stuff, runs lower temps and doesn't seem to break down when hot.

- Jeff

 

[marc olivares]

i've got the Amsoil synthetic fluid in mine.... been in there for about 20k now and so far so good.
could i tell a difference?....no
does it cost more?....yes
will it take higher temps?... well that's what they claim
am i 100% sold?....not really sure
was this any help?...probably not really

good luck with what you decide on

VIVA LA SYNTHETICS

 

[NVRover]

Mobil 1 ATF here. 123k miles on my transmission and I live in one of the hottest places in the US. So far no issues...knock on wood!!

 

[Frank84]

I agree with Marc on this - been putting castrol synthetic in a '99 DII for the last 40k miles (out of 160k) with no tangible benefits. No problems either though. The synthetics supposedly lower temperatures a little but since there's no gauge I can't prove that. I change the fluid every 15k - not a full flush, just what's in the sump. Every 30k I do the filter and clean up the sump pan and little magnet inside there.

 

[Ron]

careful switching. There have been a few failures soon after a switch to synthetic in the trans. It is the only place I still run dino.

 

[LOVE hate relationship]

Ron - I am having the transmission flushed in my 2000 Disco II on Friday. Where did you get your info on transmission faliures after switching? Thanks for any info. Oh by the way I am leaning towards flushing and filling with synthetic.
Adam

 

[sven]

careful switching. There have been a few failures soon after a switch to synthetic in the trans. It is the only place I still run dino.

I have to agree with Ron too. Ive worked in the Auto Trans business for a couple of years in the mid-90's (Im no expert by any means) but I've seen a whole bunch of crap.

Especially if its the original AT with over 100k, keep it dino. Remember that the friction material that gets burned off the clutches are suspended in the ATF. If you fully flush a trans that has wear, it MAY not function properly afterwards. I would keep it dino and change the filter and fluid the conventional way.