as i said, i been searching the forums for it but i didnt come across it. today i got my new tires on my 1988 N/a 130k miles, not sure when the last time the tranny fluid was changed but, i asked him how much it would be to change it for me, (just curious) and he said no, u dont want to change it, he said he changed it before and it messed the tranny up real bad and the guy had to get a swap done, and rx7s dont like new tranny fluid, i been trying to change all the stuff sence i just got the car a month ago( and i am lovin it), anyways confirm or deny this completely, dont tell me its debateable please thx

 

For a manual tranny thats bullshit. For an auto, its true, IF, you have never changed it.

Like if its been 10 years since you changed the auto fluid chances are that if you change it now you'll run into problems. My shop teacher told me and my class this back a few years ago, and it only applys to old auto trannys.

 

Thats the stupidest thing I've ever heard. Tranny fluid is bad? WTF! Change it out with some high quality Redline MT90 or something like that.

edit: crap too slow

 

changing tranny fluid will screw with your tranny is a MYTH! if by changing the tranny fluid a problem arises then the tranny was overdue for failure and better to have it fail in your driveway than out in the middle of BFE...

don't believe the myths, there are far too many of them out there.. i used to build trannys but i have gotten away from that aspect of auto repairs(bad back).


just be sure to use the PROPER fluid when changing it..

 

ok thanks, yea i failed to mention this is a manual( o boy inclinded stop litghs are fun!) so its looking like i m gonna go ahead and change it, is there anyway i can get a lil bit out and see about how old it looks, i know wat colors and sediments to look for. thanks

 

what kind of retard told you that changing manual transmission lube would cause a problem?

*sigh*

some people should not be working on cars...


edit: just be sure to use the proper lubricant, always!

 

the funny thing is the guy that told me this i go to church with and he happen to work at the place i decided to go get my tires done at, he never drove the car, i am not sure if he knew it was manual or not, although the way the guy that drove it drove it, i m almost sure he would tell... anyways redline is the best way to go i have read..

 

lol so your saying that the auto fluid changing is bad, is a myth? hahahha, ****, im such a sucker. My friggen mechancis teacher told me this, and he was like a god with motors (so I thought) so I never questioned his judgement.

 

i have had people tell me that too, it is like having a piece of bubblegum holding things together, it will only last so long.

 

IIRC,

there was some talk about not using Mobil one synthetic due to its high content of (Sulfur?) that damaged the brass on our syncros. Anyone want to confirm/deny that rumor?

 

synthetic is an overrated type of lubricant, it has it's place but people who think it belongs in every aspect of their vehicle are sadly mistaken.

 

I am actually not going to dispute that point, I was just pointing out that in certain cases, synthetics can be detrimental.

 

BEFORE DRAINING THE TRANNY FLUID, REMOVE THE TRANNY FILLER PLUG. I lost count of all the people on this board who drain the fluid out of the tranny and can't refill it because they cant get the filler plug off.

 

Amen to getting the filler plugs out of the tranny and differential. I have an 89 GTU that has manual of course. I was going to make the change yesterday and the tranny plug is frozen in place. I put some penetrating oil on its threads and will see if that loosens things. I didn't have the correct socket size for the diff. filler plug, 13/16" was too big and 7/8" was too small. Anyone know the correct metric size for the diff. filler plug?

Luckily I tried removing the filler plugs before I drained either the diff or tranny. I assumed that I'd have to take both out at some point and taking them out at the beginning would ventilate the reservoirs and help 'em to drain faster as well as insure they could be removed. I had no problems loosening either drain plugs, but the filler plugs were very tight and couldn't be loosened with the tools I had. Anyone have any secrets on loosening the filler plugs and what is the best tool to use to get the new flluid into the filler holes. Access to both is very restricted.

 

When I checked around this forum prior to rebuilding the manual tranny in my 88, I asked the question of what's the best fluid--they came back from a shop in Canada--NEO! I have to agree. Now the tranny shifts great, very smooth, and its several thousand miles old, with no synchro problems--or any of that other crap! Mabey thats why F1 and Nascar racers use it too.

 

After letting the filler plugs soak up the penetrating oil overnight I was able to finally get them loose and had no problems changing both the differential oil and tranny oil by using gravity feed and a little air pressure to push the diff oil up into the filler hole. Put new washers on the drain plugs and wrapped teflon tape on the threads. By the way, I needed a 23mm socket to fit the differential filler plug.

This is an easy job once you've removed the filler plugs and figured out how to gravity feed or force the oil into the filler holes. I think it took a couple hours to drain, fill and check both the tranny and differential.

 

For automatics this can be true. ATF contains lots of detergents in it to prevent sludge buildup. After 50-60k miles most of the detergents are gone or inactive. If you continue driving your automatic vehicle then sludge can buildup inside the tranny. The tranny will continue working normally for many miles. If you decide to later, lets say 100k miles, to replace your ATF you can cause problems because the detergents in the fresh fluid can dislodge the sludge and clog valves and tiny passages in an auto tranny.

Its not myth but true. I see auto's fail all of the time after their owners decided its better than late to replace their ATF.

 

for manuals: replace=GOOD
I used Redline MT-90 synthetic with great results in my '88 N/A 5-speed.

 

It's sort of a half truth. If the transmission seals are worn, and the syncros are on their way out, putting in fresh oil can often make the transmission leak and shift poorly.

The reason is that it was the GRIT and DIRT in the fluid that was creating friction to allow the syncros to do their job, and that same crap was sealing the minor tears and leaks in the seals. The new oil is much more slippery, so the syncros slip and cause the grind. And it can seep through the worn seals. This can be especially true when switching from regular to synthetic oil.

But if this happens, the transmission was already on the way out. So it really wasn't the new oil that caused the failures, it only made them obvious.