Hello, i have a 91 Explorer 4.0 4x4

25

Asked by Dec 08, 2014 at 10:34 PM about the 1991 Ford Explorer 4 Dr Eddie Bauer 4WD SUV

Question type: Maintenance & Repair

Hello, i have a 91 Explorer 4.0 4x4 and the front seal in the tranny went out and of course
all thje tranny fluid came out on the hwy. First would it be type F or the mercon? second
ive always heard that iof the tranny had high miles and never had the fluid changed you
shouldnt because the tranny would probably fail, is this true?

2 Answers

20,975

I know some shops won't change the fluid in a high-mileage trans because they are leery of stirring up all those potential metal shavings in the bottom of the pan or filter, but that's just wrong, do a proper flush and filter change and it'll last longer. Amsoil recommends that on high-mileage trans that have never been serviced that a second filter/fluid change be done a few weeks after the first, this is to catch all the sludge the detergent properties of the new fluid is likely to loosen in the old trans and gunk up the new filter even worse than the old one. Here is their quote: ------------ "Most of the transmission failures after an evacuation (fluid exchange machine) service have occurred primarily on relatively high mileage transmissions that have not been serviced in some time. One reason for this is that the sludge and dirt buildup within the transmission will not completely be removed during the service. When the new fluid (which has detergent properties) is placed in the transmission, over days and weeks, the internal components begin to wash the insides of the transmission. This sludge does finally work loose and settles in the transmission filter, clogging it up even further than it may have been before service. In these extreme cases, where service has not been performed in some time, changing the filter may not completely fix the problem. Some mechanics recommend a second service a few weeks after the first, replacing the filter again, which may be partially clogged due to the cleaning process in the transmission."

5,035

Even if you change your transmission filter at regular intervals per guidelines, it's still amazing how much sediment can end up in the valve body. I pulled the valve body on my Ford AODE transmission in part because of an idiot Ford mechanic and improper warranty work years before. Anyway, in every passage of the valve body was a layer of sediment and that included many of the micro holes. Afterwards the shifts were quicker and firmer. Can you imagine the probable sediment in the valve body of a high mileage neglected trans?

Your Answer

Add photo

Related Questions

Search Ford Explorer Questions

Ford Explorer Experts

#1 OJ
OJ
Reputation 9,350
#2 Tom Demyan
Tom Demyan
Reputation 3,720
#3 tennisshoes
tennisshoes
Reputation 2,130
View All

Related Models For Sale

Used Ford F-150
2,880 Great Deals out of 212,656 listings starting at $1,000
Used Toyota 4Runner
328 Great Deals out of 20,882 listings starting at $1,990
Used Nissan Pathfinder
407 Great Deals out of 25,072 listings starting at $999
Used GMC Yukon
550 Great Deals out of 17,369 listings starting at $1,995

Used Cars For Sale

2017 Ford Explorer For Sale
19 Great Deals out of 44,193 listings starting at $24,490
2016 Ford Explorer For Sale
178 Great Deals out of 5,985 listings starting at $16,900
2015 Ford Explorer For Sale
149 Great Deals out of 3,480 listings starting at $13,595
2014 Ford Explorer For Sale
279 Great Deals out of 6,042 listings starting at $11,400
2013 Ford Explorer For Sale
147 Great Deals out of 4,000 listings starting at $9,000